Detection of Oxidative Damage in Response to Protein Misfolding in the Endoplasmic Reticulum

Gramine Exerts Cytoprotective Effects and Antioxidant Properties Against H2O2-Induced Oxidative Stress in HEK 293 Cells

Oxidative stress caused due to the perturbations in the oxidant-antioxidant system can damage molecules and cause cellular alteration leading to the pathogenesis of multiple diseases. This study was designed and performed to investigate the antioxidant and anti-inflammatory effects of an alkaloid, gramine on H2O2-induced oxidative stress on HEK 293 cells. Cell viability and morphometric analysis of cells treated with H2O2 and gramine were studied. Oxidative stress and inflammatory and antioxidant enzymes such as ROS, LPO, NO, SOD, GSH, and CAT were analyzed. Furthermore, mRNA expression of SOD, CAT, and COX-2 was also evaluated. H2O2 at concentration > 0.3 mM and gramine at concentration > 80 μg/mL affect the proliferation. Viability and morphometric analysis showed that gramine has protective effects. Treating cells with gramine suppressed oxidative stress and inflammatory enzymes, whereas antioxidant enzymes were enhanced. SOD and CAT mRNA levels were overexpressed and COX-2 mRNA levels were decreased in the treated groups. Gramine possesses effective antioxidant potential and can regulate oxidative stress and damages associated with it.

Tauroursodeoxycholic Acid Supplementation in In Vitro Culture of Indicine Bovine Embryos: Molecular and Cellular Effects on the In Vitro Cryotolerance

During embryo development, the endoplasmic reticulum (ER) acts as an important site for protein biosynthesis; however, in vitro culture (IVC) can negatively affect ER homeostasis. Therefore, the aim of our study was to evaluate the effects of the supplementation of tauroursodeoxycholic acid (TUDCA), an ER stress inhibitor, in the IVC of bovine embryos. Two experiments were carried out: Exp. 1: an evaluation of blastocyst rate, hatching kinetics, and gene expression of hatched embryos after being treated with different concentrations of TUDCA (50, 200, or 1000 μM) in the IVC; Exp. 2: an evaluation of the re-expansion, hatching, and gene expression of hatched embryos previously treated with 200 µM of TUDCA at IVC and submitted to vitrification. There was no increase in the blastocyst and hatched blastocyst rates treated with TUDCA in the IVC. However, embryos submitted to vitrification after treatment with 200 µM of TUDCA underwent an increased hatching rate post-warming together with a down-regulation in the expression of ER stress-related genes and the accumulation of lipids. In conclusion, this work showed that the addition of TUDCA during in vitro culture can improve the cryotolerance of the bovine blastocyst through the putative modulation of ER and oxidative stress.

Sinapic acid-loaded gel accelerates diabetic wound healing process by promoting re-epithelialization and attenuating oxidative stress in rats

Impaired wound healing is a critical health concern for individuals with diabetes. Sinapic acid, a phyto-compound, has wound-healing potential owing to its various bioactivities. In this study, we explored the wound-healing ability of sinapic acid in diabetes. Full-thickness excisional wounds were created in streptozotocin-induced diabetic rats. Sinapic acid-loaded gels (1%, 2%, and 3%) were prepared and applied topically to diabetic skin wounds. On day 7 post-wounding, rats were sacrificed, and macroscopic, histopathological, and oxidative markers of wound healing activity were evaluated in the collected wound tissues. Sinapic acid-loaded gels showed better recovery in re-epithelialization (p < 0.05) and angiogenesis (p < 0.05) compared to the negative control group. Sinapic acid-loaded gels (1%, 2%, and 3%) showed 87.46%, 79.53%, and 68.78% wound contraction, respectively. They increased collagen content (28.05 ± 1.66, 17.30 ± 2.19, and 11.64 ± 1.25, respectively) and decreased malondialdehyde (MDA) levels (17.49 ± 1.61, 18.44 ± 1.24, and 19.16 ± 1.77, respectively) compared to the negative control group (6.76 ± 0.89, and 43.58 ± 3.70, respectively) (p < 0.05). Moreover, sinapic acid-loaded gel groups demonstrated enhanced antioxidant capacity (approximately 2-2.5-fold) compared to the negative control group (p < 0.05). Sinapic acid 1% loaded gel showed the best effect on the diabetic healing process, whereas sinapic acid 2% loaded gel and reference drug showed similar effects. The results of this study, for the first time, suggest that the topical application of sinapic acid can promote diabetic wound healing, especially at low doses.

The healing bitterness of Gentiana lutea L., phytochemistry and biological activities: A systematic review

Over many years, natural products have been a source of healing agents and have exhibited beneficial uses for treating human diseases. The Gentiana genus is the biggest genus in the Gentianaceae, with over 400 species distributed mainly in alpine zones of temperate countries around the world. Plants in the Gentiana genus have historically been used to treat a wide range of diseases. Still, only in the last years has particular attention been paid to the biological activities of Gentiana lutea Linn., also known as yellow Gentian or bitterwort. Several in vitro/vivo investigations and human interventional trials have demonstrated the promising activity of G. lutea extracts against oxidative stress, microbial infections, inflammation, obesity, atherosclerosis, etc.. A systematic approach was performed using Pubmed and Scopus databases to update G. lutea chemistry and activity. Specifically, this systematic review synthesized the major specialized bitter metabolites and the biological activity data obtained from different cell lines, animal models, and human interventional trials. This review aims to the exaltation of G. lutea as a source of bioactive compounds that can prevent and treat several human illnesses.

Progress on microalgae cultivation in wastewater for bioremediation and circular bioeconomy

Water usage increased alongside its competitiveness due to its finite amount. Yet, many industries still rely on this finite resource thus recalling the need to recirculate their water for production. Circular bioeconomy is presently the new approach emphasizing on the 'end-of-life' concept with reusing, recycling, and recovering materials. Microalgae are the ideal source contributing to circular bioeconomy as it exhibits fast growth and adaptability supported by biological rigidity which in turn consumes nutrients, making it an ideal and capable bioremediating agent, therefore allowing water re-use as well as its biomass potential in biorefineries. Nevertheless, there are challenges that still need to be addressed with consideration of recent advances in cultivating microalgae in wastewater. This review aimed to investigate the potential of microalgae biomass cultivated in wastewater. More importantly, how it'll play a role in the circular bioeconomy. This includes an in-depth look at the production of goods coming from wastes tattered by emerging pollutants. These emerging pollutants include microplastics, antibiotics, ever-increasingly sewage water, and heavy metals which have not been comprehensively compared and explored. Therefore, this review is aiming to bring new insights to researchers and industrial stakeholders with interest in green alternatives to eventually contribute towards environmental sustainability.

Fine particulate matter induces heart defects via AHR/ROS-mediated endoplasmic reticulum stress

Accumulating body of evidence indicates that exposure to fine particulate matter (PM_2.5) is closely associated with congenital heart disease in the offspring, but the underlying molecular mechanisms remain to be elucidated. We previously reported that extractable organic matter (EOM) from PM_2.5 induces reactive oxygen species (ROS) overproduction by activating aromatic hydrocarbon receptor (AHR), leading to heart defects in zebrafish embryos. We hypothesized that endoplasmic reticulum (ER) stress might be elicited by the excessive ROS production and thereby contribute to the cardiac developmental toxicity of PM_2.5. In this study, we examined the effects of EOM on endoplasmic reticulum (ER) stress, apoptosis, and Wnt signal pathway in zebrafish embryos, and explored their roles in EOM-induced heart defects. Our results showed that 4-Phenylbutyric acid (4-PBA), a pharmaceutical inhibitor of ER stress, significantly attenuated the EOM-elevated heart malformation rates. Moreover, EOM upregulated the expression levels of ER stress marker genes including CHOP and PDI in the heart of zebrafish embryos, which were counteracted by genetic or pharmaceutical inhibition of AHR activity. The ROS scavenger N-Acetyl-l-cysteine (NAC) also abolished the EOM-induced ER stress. We further demonstrated that both 4-PBA and CHOP genetic knockdown rescued the PM_2.5-induced ROS overproduction, apoptosis and suppression of Wnt signaling. In conclusion, our results indicate that PM_2.5 induces AHR/ROS-mediated ER stress, which leads to apoptosis and Wnt signaling inhibition, ultimately resulting in heart defects.

Dietary Intervention with Blackcurrant Pomace Protects Rats from Testicular Oxidative Stress Induced by Exposition to Biodiesel Exhaust

The exposure to diesel exhaust emissions (DEE) contributes to negative health outcomes and premature mortality. At the same time, the health effects of the exposure to biodiesel exhaust emission are still in scientific debate. The aim of presented study was to investigate in an animal study the effects of exposure to DEE from two types of biodiesel fuels, 1st generation B7 biodiesel containing 7% of fatty acid methyl esters (FAME) or 2nd generation biodiesel (SHB20) containing 7% of FAME and 13% of hydrotreated vegetable oil (HVO), on the oxidative stress in testes and possible protective effects of dietary intervention with blackcurrant pomace (BC). Adult Fisher344/DuCrl rats were exposed by inhalation (6 h/day, 5 days/week for 4 weeks) to 2% of DEE from B7 or SHB20 fuel mixed with air. The animals from B7 (n = 14) and SHB20 (n = 14) groups subjected to filtered by a diesel particulate filter (DPF) or unfiltered DEE were maintained on standard feed. The rats from B7+BC (n = 12) or SHB20+BC (n = 12), exposed to DEE in the same way, were fed with feed supplemented containing 2% (m/m) of BC. The exposure to exhaust emissions from 1st and 2nd generation biodiesel resulted in induction of oxidative stress in the testes. Higher concentration of the oxidative stress markers thiobarbituric acid-reactive substances (TBARS), lipid hydroperoxides (LOOHs), 25-dihydroxycholesterols (25(OH)2Ch), and 7-ketocholesterol (7-KCh) level), as well as decreased level of antioxidant defense systems such as reduced glutathione (GSH), GSH/GSSG ratio, and increased level of oxidized glutathione (GSSG)) were found. Dietary intervention reduced the concentration of TBARS, 7-KCh, LOOHs, and the GSSG level, and elevated the GSH level in testes. In conclusion, DEE-induced oxidative stress in the testes was related to the biodiesel feedstock and the application of DPF. The SHB20 DEE without DPF technology exerted the most pronounced toxic effects. Dietary intervention with BC in rats exposed to DEE reduced oxidative stress in testes and improved antioxidative defense parameters, however the redox balance in the testes was not completely restored.

Sensitivity of Zebrafish Embryogenesis to Risk of Fotemustine Exposure

Several anthropogenic products in wastewater are considered a threat to the aquatic environment. In addition to common industrial pollutants, levels of pharmaceuticals have been increasingly found in the environment in recent years, which may present a strong risk to the aquatic species that live there. The constant consumption of biologically active chemicals for human health has been matched by an increase in the leaking of these compounds in natural habitats over the last two decades. This study is aimed at evaluating the developmental toxicity of fotemustine in the ecological environment. Zebrafish embryos were exposed to doses of 25, 50 and 100 µg/mL from 4 h post-fertilization to 120 h. This study confirms that fotemustine exposure at 50 and 100 µg/mL affects the survival and hatching rate, morphology score and body length. Additionally, it significantly disturbs the antioxidant defense system and increases ROS in zebrafish larvae. From the molecular point of view, fotemustine exposure strongly induces apoptosis, endoplasmic reticulum stress (ERS) and the Wnt signaling pathway.

Two Tautomers of Thiobarbituric Acid in One Crystal: The Experimental Charge Density Perspective

High-quality crystals of a certain polymorphic form of thiobarbituric acid containing both keto and enol tautomers in the asymmetric unit were obtained. High-resolution X-ray diffraction data up to sinθ/λ = 1.0 Å^-1 were collected and subsequently successfully used for the refining of the multipolar model of electron density distribution. The use of a crystal containing both ketone and enol forms allowed a direct comparison of the topological analysis results and a closer look at the differences between these two forms. The similarities and differences between the deformation densities, electrostatic potentials, Laplacian maps and bond characteristics of the tautomers were analysed. Additionally, the spectrum of the intermolecular interactions was identified and studied from classical, relatively strong N-H···O and O-H···O hydrogen bonds through weaker N-H···S hydrogen bonds to weak interactions (for instance, C-H···O, C-H···S and N···O). The results of these studies point toward the importance of including both the geometrical features and the details of the electron density distribution in the analysis of such weak interactions.

Lipid peroxidation derived reactive carbonyl species in free and conjugated forms as an index of lipid peroxidation: limits and perspectives

Reactive carbonyl species (RCS) formed by lipidperoxidation as free forms or as enzymatic and non-enzymatic conjugates are widely used as an index of oxidative stress. Besides general measurements based on derivatizing reactions, more selective and sensitive MS based analyses have been proposed in the last decade. Untargeted and targeted methods for the measurement of free RCS and adducts have been described and their applications to in vitro and ex vivo samples have permitted the identification of many biological targets, reaction mechanisms and adducted moieties with a particular relevance to RCS protein adducts. The growing interest in protein carbonylation can be explained by considering that protein adducts are now recognized as being involved in the damaging action of oxidative stress so that their measurement is performed not only to obtain an index of lipid peroxidation but also to gain a deeper insight into the molecular mechanisms of oxidative stress. The aim of the review is to discuss the most novel analytical approaches and their application for profiling reactive carbonyl species and their enzymatic and non-enzymatic metabolites as an index of lipid-oxidation and oxidative stress. Limits and perspectives will be discussed.

Protein Homeostasis Networks and the Use of Yeast to Guide Interventions in Alzheimer's Disease

Alzheimer's Disease (AD) is a progressive multifactorial age-related neurodegenerative disorder that causes the majority of deaths due to dementia in the elderly. Although various risk factors have been found to be associated with AD progression, the cause of the disease is still unresolved. The loss of proteostasis is one of the major causes of AD: it is evident by aggregation of misfolded proteins, lipid homeostasis disruption, accumulation of autophagic vesicles, and oxidative damage during the disease progression. Different models have been developed to study AD, one of which is a yeast model. Yeasts are simple unicellular eukaryotic cells that have provided great insights into human cell biology. Various yeast models, including unmodified and genetically modified yeasts, have been established for studying AD and have provided significant amount of information on AD pathology and potential interventions. The conservation of various human biological processes, including signal transduction, energy metabolism, protein homeostasis, stress responses, oxidative phosphorylation, vesicle trafficking, apoptosis, endocytosis, and ageing, renders yeast a fascinating, powerful model for AD. In addition, the easy manipulation of the yeast genome and availability of methods to evaluate yeast cells rapidly in high throughput technological platforms strengthen the rationale of using yeast as a model. This review focuses on the description of the proteostasis network in yeast and its comparison with the human proteostasis network. It further elaborates on the AD-associated proteostasis failure and applications of the yeast proteostasis network to understand AD pathology and its potential to guide interventions against AD.

Bioactive proteins and phytochemicals from legumes: Mechanisms of action preventing obesity and type-2 diabetes

The Fabaceae family of plants include a variety of seeds with multiple shapes, sizes, and colors; with a great diversity of bioactive compounds found in legume seeds. Legumes are an excellent source of protein, peptides and phytochemicals which are present in significant amounts. These bioactive compounds have been reported to reduce the risk of developing non-communicable diseases (NCD), such as obesity and type-2 diabetes. In this narrative review, we discuss the biological potential of bioactive compounds found in legumes and the health benefits associated with their consumption as an alternative approach in the management of NCD. Current extraction methods, characteristics of the bioactive compounds, and different in vitro and in vivo studies evaluating the bioactivity of legume bioactives are reviewed and discussed.

Role of endoplasmic reticulum stress on developmental competency and cryo-tolerance in bovine embryos

Endoplasmic reticulum (ER) stress, a dysfunction in protein folding capacity of the ER, is involved in many physiological responses including mammalian reproductive systems. Studies have shown that ER stress interferes with the developmental process of in vitro oocyte maturation and embryo development; however, little is known about its effects on bovine preimplantation embryonic development. In this study, we examined the effects of ER stress during IVC on developmental competency and cryo-tolerance in bovine embryos. IVF-derived zygotes were cultured in CR1aa medium supplemented with tauroursodeoxycholic acid (TUDCA) and/or tunicamycin (TM), which are ER stress-inhibitory and stress-inducing agents, respectively, for 8 days. TM treatment decreased the blastocyst developmental rate and increased the percentage of apoptotic cells compared to that in the control group (10.2 ± 2.3% vs. 39.75 ± 1.3% and 17.8 ± 1.2% vs. 3.6 ± 1.1%, respectively; P < 0.01). However, the blastocyst developmental rate was increased and the percentage of apoptotic cells was decreased by addition of TUDCA in IVC medium compared to that in the control group (50.9 ± 0.9% vs. 39.75 ± 1.3% and 1.13 ± 1.0% vs. 3.6 ± 1.1%, respectively; P < 0.01). Importantly, in the group treated with TM plus TUDCA, the developmental rate and the percentage of apoptotic cells in blastocysts were similar to that in the control group, indicating that TUDCA ameliorates the adverse effects of TM alone on embryo development. In addition, TUDCA treatment significantly reduced the reactive oxygen species, expression of ER stress (GRP78, ATF4, ATF6, IER1, and sXBP1) and pro-apoptotic (CHOP and BAX) genes, while it increased anti-apoptotic BCL2 gene expression and glutathione levels. Moreover, TUDCA improved blastocyst cryo-tolerance as marked by a significantly increased hatching rate and decreased the number of apoptotic cells recorded at 48 h after a post-warming. Therefore, in concordance with a previous report in mice or pig, we showed that TUDCA supplementation during IVC increases the developmental competency of bovine in vitro-derived embryos. Additionally, we found that the presence of TUDCA in IVC medium improves the cryo-tolerance of bovine embryos. These results suggest that modulation of ER stress during IVC contributes to the production of high-quality bovine embryos in terms of cryo-tolerance.

Endoplasmic Reticulum (ER) Stress and Unfolded Protein Response (UPR) in Mammalian Oocyte Maturation and Preimplantation Embryo Development

Mammalian oocytes and early embryos derived from in vitro production are highly susceptible to a variety of cellular stresses. During oocyte maturation and preimplantation embryo development, functional proteins must be folded properly in the endoplasmic reticulum (ER) to maintain oocyte and embryo development. However, some adverse factors negatively impact ER functions and protein synthesis, resulting in the activation of ER stress and unfolded protein response (UPR) signaling pathways. ER stress and UPR signaling have been identified in mammalian oocytes and embryos produced in vitro, suggesting that modulation of ER stress and UPR signaling play very important roles in oocyte maturation and the development of preimplantation embryos. In this review, we briefly describe the current state of knowledge regarding ER stress, UPR signaling pathways, and their roles and mechanisms in mammalian (excluding human) oocyte maturation and preimplantation embryo development.

Myo-inositol oxygenase accentuates renal tubular injury initiated by endoplasmic reticulum stress

Besides oxidant stress, endoplasmic reticulum (ER) stress has been implicated in the pathogenesis of various metabolic disorders affecting the kidney. These two forms of stresses are not mutually exclusive to each other and may operate by a feedback loop in worsening the cellular injury. To attest to this contention, studies were performed to assess whether in such a setting, there is worsening of tubulointerstitial injury. We employed tunicamycin as a model of ER stress and used tubular cells and mice overexpressing myo-inositol oxygenase (MIOX), an enzyme involved in glycolytic events with excessive generation of ROS. Concomitant treatment of tunicamycin and transfection of cells with MIOX-pcDNA led to a marked generation of ROS, which was reduced by MIOX-siRNA. Likewise, an accentuated expression of ER stress sensors, GRP78, XBP1, and CHOP, was observed, which was reduced with MIOX-siRNA. These sensors were markedly elevated in MIOX-TG mice compared with WT treated with tunicamycin. This was accompanied with marked deterioration of tubular morphology, along with impairment of renal functions. Interestingly, minimal damage and elevation of ER stressors was observed in MIOX-KO mice. Downstream events that were more adversely affected in MIOX-TG mice included accentuated expression of proapoptogenic proteins, proinflammatory cytokines, and extracellular matrix constituents, although expression of these molecules was unaffected in MIOX-KO mice. Also, their tunicamycin-induced accentuated expression in tubular cells was notably reduced with MIOX-siRNA. These studies suggest that the biology of MIOX-induced oxidant stress and tunicamycin-induced ER stress are interlinked, and both of the events may feed into each other to amplify the tubulointerstitial injury.

Xiaoaiping Induces Developmental Toxicity in Zebrafish Embryos Through Activation of ER Stress, Apoptosis and the Wnt Pathway

The aim of the study was to determine the developmental toxicity of the traditional Chinese medicine Xiaoaiping (XAP) and to investigate its underlying mechanism of action. Zebrafish embryos were incubated with 0.4, 0.8, 1.2, and 1.6 mg/mL XAP. Endpoints such as mortality, hatching rate, malformation, body length, morphology score, swimming behavior, histological changes, reactive oxygen species (ROS) production, total superoxide dismutase (T-SOD) activity, and the mRNA expression of genes related to oxidative stress, endoplasmic reticulum (ER) stress, apoptosis, and the Wnt pathway were evaluated. Our results demonstrated that XAP exposure increased mortality and malformation and reduced the hatching rate. XAP resulted in severe malformation, including swim bladder deficiency, yolk retention, pericardial edema, and tail curvature. Histopathological analysis showed that XAP induced liver, heart and muscle injury. High doses (≥1.2 mg/mL) of XAP notably decreased the locomotor capacity of zebrafish. ROS generation was remarkably increased and T-SOD activity was decreased, confirming that oxidative stress was induced by XAP. The mRNA expression levels of ER stress-related genes (chop, hspa5, hsp90b1, and perk), apoptosis-related genes (caspase-3, bax, and p53) and wnt11 were significantly upregulated by XAP exposure. The expression levels of the oxidative stress-related genes (cat, sod1, and gstp2), Wnt pathway-related genes (β-catenin, wnt3a, and wnt8a) and bcl-2 initially increased and then decreased as the XAP exposure dose increased. In conclusion, we provide evidence for the first time that XAP can induce dose-related developmental toxicity, and ER stress, apoptosis and the Wnt pathway participate in the toxicity regulation.

The Role of Oxidative Stress, Mitochondrial Function, and Autophagy in Diabetic Polyneuropathy

Diabetic polyneuropathy (DPN) is the most frequent and prevalent chronic complication of diabetes mellitus (DM). The state of persistent hyperglycemia leads to an increase in the production of cytosolic and mitochondrial reactive oxygen species (ROS) and favors deregulation of the antioxidant defenses that are capable of activating diverse metabolic pathways which trigger the presence of nitro-oxidative stress (NOS) and endoplasmic reticulum stress. Hyperglycemia provokes the appearance of micro- and macrovascular complications and favors oxidative damage to the macromolecules (lipids, carbohydrates, and proteins) with an increase in products that damage the DNA. Hyperglycemia produces mitochondrial dysfunction with deregulation between mitochondrial fission/fusion and regulatory factors. Mitochondrial fission appears early in diabetic neuropathy with the ability to facilitate mitochondrial fragmentation. Autophagy is a catabolic process induced by oxidative stress that involves the formation of vesicles by the lysosomes. Autophagy protects cells from diverse stress factors and routine deterioration. Clarification of the mechanisms involved in the appearance of complications in DM will facilitate the selection of specific therapeutic options based on the mechanisms involved in the metabolic pathways affected. Nowadays, the antioxidant agents consumed exogenously form an adjuvant therapeutic alternative in chronic degenerative metabolic diseases, such as DM.

The effect of follicle size and homogeneity of follicular development on the morphokinetics of human embryos

Purpose

Our aim was to investigate follicular size (large, ≥17 mm and small, <17 mm) at the time of OPU and homogeneity of follicular development (homogenous development: follicles being present in a homogenous spread of all sizes; heterogeneous: a predominance of small and large follicles) by analysing the morphokinetics of embryo development.

Methods

In this prospective cohort study, 2526 COCs belonging to 187 patients were cultured to day 5. Embryos were evaluated morphokinetically. Four subgroups were defined: large follicles from heterogeneous cycles (LHet) and homogenous cycles (LHom) and small follicles from heterogeneous cycles (SHet) and homogenous cycles (SHom).

Results

Rates of fertilization, blastocyst formation and top and good quality blastocysts were found to be significantly higher in embryos from the LHom group (p < 0.001; p < 0.001; p < 0.001). Small follicles from both homogenous and heterogeneous cycles had significantly lower blastocyst formation and top and good quality blastocyst rates (p < 0.001; p < 0.001). Embryos from SHet had significantly more direct cleavages (p = 0.011). Time to reach blastocyst was shorter in SHom than LHet and LHom (p = 0.002; p = 0.027, respectively). However, once the blastocyst stage was achieved, implantation rates were not significantly different between subgroups, the highest rate being observed in the LHom group. Multivariable analysis revealed that homogeneity of follicular development and follicular size had a significant effect on blastocyst development and quality (p = 0.049; p < 0.001, respectively).

Conclusion

Follicular dynamics, illustrated by follicular size and homogeneity of follicular development, influence early human embryo development. Patterns of follicular growth have an impact on embryo quality and viability which is reflected in morphokinetic variables.

Electronic supplementary material

The online version of this article (doi:10.1007/s10815-017-0935-1) contains supplementary material, which is available to authorized users.

Tauroursodeoxycholic acid improves pre-implantation development of porcine SCNT embryo by endoplasmic reticulum stress inhibition

The aim of this study is to investigate whether endoplasmic reticulum (ER) stress attenuation could improve porcine somatic cell nuclear transfer (SCNT) embryo developmental competence. We treated porcine SCNT embryos with TUDCA (tauroursodeoxycholic acid, an inhibitor of ER stress) and/or TM (tunicamycin, an ER stress inducer), and examined embryonic developmental potential, embryo quality, the levels of ER stress markers (XBP1 protein and mRNA) and apoptosis-related-genes (BAX and BCL2 mRNA). Immunostaining detected X-box-binding protein (XBP1), a key gene regulator during ER stress, at all stages of SCNT embryo development. Embryo development analysis revealed that TUDCA treatment markedly increased (p<0.05) blastocyst formation rate, total cell number and inner cell mass (ICM) cell number compared to untreated control group. The TUDCA and TM groups showed significant alterations in XBP1 protein and XBP1-s mRNA levels compared to controls (lower and higher, respectively; p<0.05). Also, TUDCA treatment reduced oxidative stress by up-regulation of the antioxidant, GSH. TUNEL assay showed that TUDCA treatment significantly reduced apoptosis in porcine SCNT blastocysts confirmed by decreased pro-apoptotic BAX and increased anti-apoptotic BCL2 mRNA levels. Collectively, our results indicated that TUDCA can enhance the developmental potential of porcine SCNT embryos by attenuating ER-stress and reducing apoptosis.

Nitrosative Stress, Hypernitrosylation, and Autoimmune Responses to Nitrosylated Proteins: New Pathways in Neuroprogressive Disorders Including Depression and Chronic Fatigue Syndrome

Nitric oxide plays an indispensable role in modulating cellular signaling and redox pathways. This role is mainly effected by the readily reversible nitrosylation of selective protein cysteine thiols. The reversibility and sophistication of this signaling system is enabled and regulated by a number of enzymes which form part of the thioredoxin, glutathione, and pyridoxine antioxidant systems. Increases in nitric oxide levels initially lead to a defensive increase in the number of nitrosylated proteins in an effort to preserve their function. However, in an environment of chronic oxidative and nitrosative stress (O&NS), nitrosylation of crucial cysteine groups within key enzymes of the thioredoxin, glutathione, and pyridoxine systems leads to their inactivation thereby disabling denitrosylation and transnitrosylation and subsequently a state described as "hypernitrosylation." This state leads to the development of pathology in multiple domains such as the inhibition of enzymes of the electron transport chain, decreased mitochondrial function, and altered conformation of proteins and amino acids leading to loss of immune tolerance and development of autoimmunity. Hypernitrosylation also leads to altered function or inactivation of proteins involved in the regulation of apoptosis, autophagy, proteomic degradation, transcription factor activity, immune-inflammatory pathways, energy production, and neural function and survival. Hypernitrosylation, as a consequence of chronically elevated O&NS and activated immune-inflammatory pathways, can explain many characteristic abnormalities observed in neuroprogressive disease including major depression and chronic fatigue syndrome/myalgic encephalomyelitis. In those disorders, increased bacterial translocation may drive hypernitrosylation and autoimmune responses against nitrosylated proteins.

Effects of a Sublethal and Transient Stress of the Endoplasmic Reticulum on the Mitochondrial Population

Endoplasmic reticulum (ER) and mitochondria are not discrete intracellular organelles but establish close physical and functional interactions involved in several biological processes including mitochondrial bioenergetics, calcium homeostasis, lipid synthesis, and the regulation of apoptotic cell death pathways. As many cell types might face a transient and sublethal ER stress during their lifetime, it is thus likely that the adaptive UPR response might affect the mitochondrial population. The aim of this work was to study the putative effects of a non-lethal and transient endoplasmic reticulum stress on the mitochondrial population in HepG2 cells. The results show that thapsigargin and brefeldin A, used to induce a transient and sublethal ER stress, rapidly lead to the fragmentation of the mitochondrial network associated with a decrease in mitochondrial membrane potential, O2 (•-) production and less efficient respiration. These changes in mitochondrial function are transient and preceded by the phosphorylation of JNK. Inhibition of JNK activation by SP600125 prevents the decrease in O2 (•-) production and the mitochondrial network fragmentation observed in cells exposed to the ER stress but has no impact on the reduction of the mitochondrial membrane potential. In conclusion, our data show that a non-lethal and transient ER stress triggers a rapid activation of JNK without inducing apoptosis, leading to the fragmentation of the mitochondrial network and a reduction of O2 (•-) production. J. Cell. Physiol. 231: 1913-1931, 2016. © 2015 Wiley Periodicals, Inc.

The Role of Damage-Associated Molecular Patterns (DAMPs) in Human Diseases: Part II: DAMPs as diagnostics, prognostics and therapeutics in clinical medicine

This article is the second part of a review that addresses the role of damage-associated molecular patterns (DAMPs) in human diseases by presenting examples of traumatic (systemic inflammatory response syndrome), cardiovascular (myocardial infarction), metabolic (type 2 diabetes mellitus), neurodegenerative (Alzheimer's disease), malignant and infectious diseases. Various DAMPs are involved in the pathogenesis of all these diseases as they activate innate immune machineries including the unfolded protein response and inflammasomes. These subsequently promote sterile autoinflammation accompanied, at least in part, by subsequent adaptive autoimmune processes. This review article discusses the future role of DAMPs in routine practical medicine by highlighting the possibility of harnessing and deploying DAMPs either as biomarkers for the appropriate diagnosis and prognosis of diseases, as therapeutics in the treatment of tumours or as vaccine adjuncts for the prophylaxis of infections. In addition, this article examines the potential for developing strategies aimed at mitigating DAMPs-mediated hyperinflammatory responses, such as those seen in systemic inflammatory response syndrome associated with multiple organ failure.

Stress signaling in mammalian oocytes and embryos: a basis for intervention and improvement of outcomes

Oocytes and early stage embryos are highly sensitive to variation in diverse exogenous factors such as temperature, osmolarity, oxygen, nutrient restriction, pH, shear stress, toxins, amino acid availability, and lipids. It is becoming increasingly apparent that many such factors negatively affect the endoplasmic reticulum, protein synthesis and protein processing, initiating ER stress and unfolded protein responses. As a result, ER stress signaling serves as a common mediator of cellular responses to diverse stressors. In oocytes and embryos, this leads to developmental arrest and epigenetic changes. Recent studies have revealed that preventing ER stress or inhibiting ER stress signaling can preserve or even enhance oocyte and embryo developmental potential. This review examines ER stress signaling, how it arises, how it affects oocytes and embryos, and how its occurrence can be managed or prevented.

Endoplasmic reticulum stress signaling in mammalian oocytes and embryos: life in balance

Mammalian oocytes and embryos are exquisitely sensitive to a wide range of insults related to physical stress, chemical exposure, and exposures to adverse maternal nutrition or health status. Although cells manifest specific responses to various stressors, many of these stressors intersect at the endoplasmic reticulum (ER), where disruptions in protein folding and production of reactive oxygen species initiate downstream signaling events. These signals modulate mRNA translation and gene transcription, leading to recovery, activation of autophagy, or with severe and prolonged stress, apoptosis. ER stress signaling has recently come to the fore as a major contributor to embryo demise. Accordingly, agents that modulate or inhibit ER stress signaling have yielded beneficial effects on embryo survival and long-term developmental potential. We review here the mechanisms of ER stress signaling, their connections to mammalian oocytes and embryos, and the promising indications that interventions in this pathway may provide new opportunities for improving mammalian reproduction and health.

Oxidative stress mediated Ca(2+) release manifests endoplasmic reticulum stress leading to unfolded protein response in UV-B irradiated human skin cells

BACKGROUND

Exposure of skin to ultraviolet (UV) radiation, an environmental stressor induces number of adverse biological effects (photodamage), including cancer. The damage induced by UV-irradiation in skin cells is initiated by the photochemical generation of reactive oxygen species (ROS) and induction of endoplasmic reticulum (ER) stress and consequent activation of unfolded protein response (UPR).

OBJECTIVE

To decipher cellular and molecular events responsible for UV-B mediated ER stress and UPR activation in skin cells.

METHODS

The study was performed on human skin fibroblast (Hs68) and keratinocyte (HaCaT) cells exposed to UV-B radiations in lab conditions. Different parameters of UVB induced cellular and molecular changes were analyzed using Western-blotting, microscopic studies and flow cytometry.

RESULTS

Our results depicted that UV-B induces an immediate ROS generation that resulted in emptying of ER Ca(2+) stores inducing ER stress and activation of PERK-peIF2α-CHOP pathway. Quenching ROS generation by anti-oxidants prevented Ca(2+) release and subsequent induction of ER stress and UPR activation. UV-B irradiation induced PERK dependent G2/M phase cell cycle arrest in Hs68 and G1/S phase cell cycle arrest in HaCaT. Also our study reflects that UV-B exposure leads to loss of mitochondrial membrane potential, activation of apoptotic cascade as evident by AnnexinV/PI staining, decreased expression of Bcl-2 and increased cleavage of PARP-1 protein.

CONCLUSION

UV-B induced Ca(2+) deficit within ER lumen was mediated by immediate ROS generation. Insufficient Ca(2+) concentration within ER lumen developed ER stress leading to UPR activation. These changes were reversed by use of anti-oxidants which quench ROS.

The effect of acetaminophen on the expression of BCRP in trophoblast cells impairs the placental barrier to bile acids during maternal cholestasis

Acetaminophen is used as first-choice drug for pain relief during pregnancy. Here we have investigated the effect of acetaminophen at subtoxic doses on the expression of ABC export pumps in trophoblast cells and its functional repercussion on the placental barrier during maternal cholestasis. The incubation of human choriocarcinoma cells (JAr, JEG-3 and BeWo) with acetaminophen for 48h resulted in no significant changes in the expression and/or activity of MDR1 and MRPs. In contrast, in JEG-3 cells, BCRP mRNA, protein, and transport activity were reduced. In rat placenta, collected at term, acetaminophen administration for the last three days of pregnancy resulted in enhanced mRNA, but not protein, levels of Mrp1 and Bcrp. In fact, a decrease in Bcrp protein was found. Using in situ perfused rat placenta, a reduction in the Bcrp-dependent fetal-to-maternal bile acid transport after treating the dams with acetaminophen was found. Complete biliary obstruction in pregnant rats induced a significant bile acid accumulation in fetal serum and tissues, which was further enhanced when the mothers were treated with acetaminophen. This drug induced increased ROS production in JEG-3 cells and decreased the total glutathione content in rat placenta. Moreover, the NRF2 pathway was activated in JEG-3 cells as shown by an increase in nuclear NRF2 levels and an up-regulation of NRF2 target genes, NQO1 and HMOX-1, which was not observed in rat placenta. In conclusion, acetaminophen induces in placenta oxidative stress and a down-regulation of BCRP/Bcrp, which may impair the placental barrier to bile acids during maternal cholestasis.