Dual effect of fetal bovine serum on early development depends on stage-specific reactive oxygen species demands in pigs

The coculture of in vitro produced porcine embryos and oviductal epithelial cells improves blastocyst formation and modify embryo quality

The efficiency of in vitro embryo production in mammals is influenced by variables associated with culture conditions during maturation, fertilization, and embryonic development. The embryos obtained often exhibit low quality due to suboptimal in vitro culture conditions compared to the in vivo environment. Co-culturing gametes and embryos with somatic cells has been developed to enhance in vitro culture conditions. This study aimed to assess the impact of coculturing in vitro-produced porcine embryos with porcine oviductal epithelial cells (POEC) on embryo development and quality. Firstly, a pure culture of POEC suitable for coculture systems was established. The epithelial origin of the cells was confirmed by the expression of E-cadherin and cytokeratin. The expression pattern of hormone receptors aligned with the diestrous oviduct, and POEC also secreted oviductal glycoprotein type 1 (OVGP-1). Secondly, POEC from passage 1 (POEC-1) were used to coculture with in vitro-produced porcine embryos. A successful coculture system was established without the addition of fetal bovine serum as a supplement. Coculturing POEC-1 in monolayers with in vitro-produced porcine embryos during the initial two days of culture enhanced the percentage of blastocysts and their hatching. Although the coculture did not alter the number of cells in the blastocysts or apoptosis assessed by TUNEL, it significantly reduced reactive oxygen species (ROS) levels in cleaved porcine embryos. This study represents the first report evaluating the quality of porcine embryos produced by IVF in coculture systems and assessing ROS levels in cleaved porcine embryos obtained by IVF.

Different Methods for Seminal Plasma Removal and Sperm Selection on the Quality and Fertility of Collared Peccary Sperm

Methods for seminal plasma (SP) removal and the selection of collared peccary sperm for fertilization were compared. The experiments evaluated the following: the (I) impact of centrifugation for SP removal before swim-up for sperm selection and (II) a comparison of different Percoll^® gradient densities (PG 45-90% and PG 35-70%). Non-selected sperm served as the control. Sperm quality was assessed based on motility patterns, morphology, membrane functional integrity, viability, reactive oxygen species (ROS), glutathione (GSH), and DNA integrity. Subsequently, the most successful group in the previous experiment and washing by centrifugation (WC) were compared for motility patterns and fertilization using pig oocytes. Swim-up decreased motility and enhanced ROS compared to the control. Centrifugation before swim-up harmed integrity and viability compared to the control. PG 45-90% (96.8 vs. 69.7 vs. 40.7 µm/s) allowed for a better velocity average pathway (VAP), a better velocity straight line, and better linearity (LIN) than those of the control and PG 35-70% (88.4 vs. 56.0 vs. 27.3 µm/s). Thus, PG 45-90% was used for fertilization. PG 45-90% obtained a higher VAP, a higher amplitude of the lateral head, straightness, and higher LIN than those of the control and WC. Cleavage (25.2-26.3%) and morula (8.1-10.5%) rates did not differ between the groups. Therefore, PG 45-90% and WC were efficient in isolating collared peccary sperm capable of fertilizing pig oocytes.

Beneficial Effects of Catalpol Supplementation during In Vitro Maturation of Porcine Cumulus-Oocyte Complexes

Oxidative stress degrades oocytes during in vitro maturation (IVM). Catalpol, a well-known iridoid glycoside, exhibits antioxidant, anti-inflammatory, and antihyperglycemic effects. In this study, catalpol supplementation was tested on porcine oocyte IVM and its mechanisms. Corticalgranule (GC) distribution, mitochondrial function, antioxidant capacity, DNA damage degree, and real-time quantitative polymerase chain reaction were used to confirm the effects of 10 μmol/L catalpol in the maturation medium during IVM. Catalpol treatment significantly increased the first-pole rate and cytoplasmic maturation in mature oocytes. It also increased oocyte glutathione (GSH), mitochondrial membrane potential and blastocyst cell number. However, DNA damage as well as reactive oxygen species (ROS) and malondialdehyde (MDA) levels. Mitochondrial membrane potential and blastocyst cell number were also increased. Thus, the supplementation of 10 μmol/L catalpol in the IVM medium improves porcine oocyte maturation and embryonic development.

Anethole improves the developmental competence of porcine embryos by reducing oxidative stress via the sonic hedgehog signaling pathway

BACKGROUND

Anethole (AN) is an organic antioxidant compound with a benzene ring and is expected to have a positive impact on early embryogenesis in mammals. However, no study has examined the effect of AN on porcine embryonic development. Therefore, we investigated the effect of AN on the development of porcine embryos and the underlying mechanism.

RESULTS

We cultured porcine in vitro-fertilized embryos in medium with AN (0, 0.3, 0.5, and 1 mg/mL) for 6 d. AN at 0.5 mg/mL significantly increased the blastocyst formation rate, trophectoderm cell number, and cellular survival rate compared to the control. AN-supplemented embryos exhibited significantly lower reactive oxygen species levels and higher glutathione levels than the control. Moreover, AN significantly improved the quantity of mitochondria and mitochondrial membrane potential, and increased the lipid droplet, fatty acid, and ATP levels. Interestingly, the levels of proteins and genes related to the sonic hedgehog (SHH) signaling pathway were significantly increased by AN.

CONCLUSIONS

These results revealed that AN improved the developmental competence of porcine preimplantation embryos by activating SHH signaling against oxidative stress and could be used for large-scale production of high-quality porcine embryos.

Arsenic exposure during porcine oocyte maturation negatively affects embryonic development by triggering oxidative stress-induced mitochondrial dysfunction and apoptosis

Arsenic (AS), an environmental contaminant, is a known human carcinogen that can cause cancer of the lung, liver, and skin. Furthermore, AS induces oxidative stress and mitochondrial impairments in mammalian cells. However, limited information is available on the effect of AS exposure on oocyte maturation of porcine, whose anatomy, physiology, and metabolism are similar to those of human. Therefore, we examined the effect of AS exposure on the in vitro maturation (IVM) of porcine oocytes and the possible underlying mechanisms. Cumulus-cell enclosed oocytes were cultured with or without AS for maturation, and then were used for analyses. This study indicated that AS under a concentration of 1 μM significantly increased the abnormal expansion of cumulus cells and the number of oocytes maintained in meiotic arrest. In addition, AS exposure significantly reduced subsequent development of embryos and increased the rate of apoptosis of blastocysts following parthenogenetic activation (PA) and in vitro fertilization (IVF). Moreover, AS exposure induced oxidative stress with increased reactive oxygen species (ROS), and decreased glutathione (GSH), leading to reduced mitochondrial membrane potential, mitochondrial quantity, DNA damage, excessive autophagy activity, and early apoptosis in porcine oocytes. Taken together, the results demonstrated that AS exposure exerts several negative effects, such as meiotic defects and embryo developmental arrest by causing mitochondrial dysfunction and apoptosis via inducing oxidative stress.

Supplementation of fetal bovine serum increased the quality of in vitro fertilized porcine embryo

Objective

The present study aimed to explain the effect of fetal bovine serum (FBS) on the in vitro production of porcine embryos and the molecular effects of FBS on the growing of porcine embryos.

Materials and Methods

Immature porcine oocytes were matured and fertilized in vitro. The resulting zygotes were cultured in porcine zygotic medium-3- until day 7 and FBS was added on day 4. Without FBS, it was treated as a control group. Quantitative real-time PCR and 2',7'-dichloro-dihydro-fluorescein diacetate (H₂DCFDA) molecular staining techniques were used to detect the expression patterns of apoptosis-associated genes and the accumulation of reactive oxygen species (ROS), respectively. Paired student's t-test was used by GraphPad Prism statistical software.

Results

FBS supplementation boosted blastocyst (BL) development and total cell count per BL substantially (p < 0.05). However, hatching and hatched BLs also increased in the FBS-treated group compared to the control. We also found that ROS accumulation in FBS-treated embryos was significantly reduced (p < 0.05) compared to the control group. The expression of the anti-apoptotic gene BCL-2 was significantly increased in FBS-treated BLs, but the pro-apoptotic gene, caspase-3 expression, was significantly reduced in FBS-treated BLs.

Conclusion

Our results suggest that FBS supplementation in porcine culture media could increase porcine embryo production by decreasing ROS accumulation and increasing the anti-apoptotic gene expression in developing BLs.

Targeted isolation of photoactive pigments from mushrooms yielded a highly potent new photosensitizer: 7,7′-biphyscion

Pigments of fungi are a fertile ground of inspiration: they spread across various chemical backbones, absorption ranges, and bioactivities. However, basidiomycetes with strikingly colored fruiting bodies have never been explored as agents for photodynamic therapy (PDT), even though known photoactive compound classes (e.g., anthraquinones or alkaloids) are used as chemotaxonomic markers. In this study, we tested the hypothesis that the dyes of skin-heads (dermocyboid Cortinarii) can produce singlet oxygen under irradiation and thus are natural photosensitizers. Three photosensitizers based on anthraquinone structures were isolated and photopharmaceutical tests were conducted. For one of the three, i.e., (–)-7,7′-biphyscion (1), a promising photoyield and photocytotoxicity of EC50 = 0.064 µM against cancer cells (A549) was found under blue light irradiation (λexc = 468 nm, 9.3 J/cm2). The results of molecular biological methods, e.g., a viability assay and a cell cycle analysis, demonstrated the harmlessness of 1 in the dark and highlighted the apoptosis-inducing PDT potential under blue light irradiation. These results demonstrate for the first time that pigments of dermocyboid Cortinarii possess a so far undescribed activity, i.e., photoactivity, with significant potential for the field of PDT. The dimeric anthraquinone (–)-7,7′-biphyscion (1) was identified as a promising natural photosensitizer.

ROMO1 is required for mitochondrial metabolism during preimplantation embryo development in pigs

Background

Reactive oxygen species (ROS) modulator 1 (ROMO1) is a mitochondrial membrane protein that is essential for the regulation of mitochondrial ROS production and redox sensing. ROMO1 regulates ROS generation within cells and is involved in cellular processes, such as cell proliferation, senescence, and death. Our purpose is to investigates the impact of ROMO1 on the mitochondria during porcine embryogenesis.

Results

We found that high expression of ROMO1 was associated with porcine preimplantation embryo development, indicating that ROMO1 may contribute to the progression of embryogenesis. Knockdown of ROMO1 disrupted porcine embryo development and blastocyst quality, thereby inducing ROS production and decreasing mitochondrial membrane potential. Knockdown of ROMO1 induced mitochondrial dysfunction by disrupting the balance of OPA1 isoforms to release cytochrome c, reduce ATP, and induce apoptosis. Meanwhile, ROMO1 overexpression showed similar effects as ROMO1 KD on the embryos. Overexpression of ROMO1 rescued the ROMO1 KD-induced defects in embryo development, mitochondrial fragmentation, and apoptosis.

Conclusions

ROMO1 plays a critical role in embryo development by regulating mitochondrial morphology, function, and apoptosis in pigs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13008-021-00076-7.

Generation of endoplasmic reticulum stress-dependent reactive oxygen species mediates TGF-β1-induced podocyte migration

Podocyte migration results in proteinuria and glomerulonephropathy. Transforming growth factor-β1 (TGF-β1), endoplasmic reticulum (ER) stress and reactive oxygen species (ROS) can mediate podocyte migration; however, the crosstalk between them is unclear. ThisGraphical Abstract study determined the relationships between these factors. ER stress biomarkers (GRP78, p-eIF2α or CHOP), intracellular ROS generation, integrin-β3 and cell adhesion and migration were studied in a treatment of experiment using TGF-β1 with and without the ER stress inhibitors: 4-phenylbutyric acid (4-PBA, a chemical chaperone), salubrinal (an eIF2α dephosphorylation inhibitor) and N-acetylcysteine (NAC, an antioxidant). ER stress biomarkers (p-eIF2α/eIF2α and GRP78), ROS generation and intergrin-β3 expression increased after TGF-β1 treatment. NAC down-regulated the expression of GRP78 after TGF-β1 treatment. 4-PBA attenuated TGF-β1-induced p-eIF2α/eIF2α, CHOP, ROS generation and intergrin-β3 expression. However, salubrinal did not inhibit TGF-β1-induced p-eIF2α/eIF2α, CHOP, ROS generation or integrin-β3 expression. NAC abrogated TGF-β1-induced integrin-β3 expression. At 24 h after treatment with TGF-β1, podocyte adhesion and migration increased. Furthermore, NAC, 4-PBA and an anti-interin-β3 antibody attenuated TGF-β1-induced podocyte adhesion and migration. This study demonstrated that TGF-β1-induced ER stress potentiates the generation of intracellular ROS to a high degree through the PERK/eIF2α/CHOP pathway. This intracellular ROS then mediates integrin-β3 expression, which regulates podocyte migration.

Reactive oxygen and nitrogen species regulate porcine embryo development during pre-implantation period: A mini-review

Significant porcine embryonic loss occurs during conceptus morphological elongation and attachment from d 10 to 20 of pregnancy, which directly decreases the reproductive efficiency of sows. A successful establishment of pregnancy mainly depends on the endometrium receptivity, embryo quality, and utero-placental microenvironment, which requires complex cross-talk between the conceptus and uterus. The understanding of the molecular mechanism regulating the uterine-conceptus communication during porcine conceptus elongation and attachment has developed in the past decades. Reactive oxygen and nitrogen species, which are intracellular reactive metabolites that regulate cell fate decisions and alter their biological functions, have recently reportedly been involved in porcine conceptus elongation and attachment. This mini-review will mainly focus on the recent researches about the role of reactive oxygen and nitrogen species in regulating porcine embryo development during the pre-implantation period.

L-Proline Activates Mammalian Target of Rapamycin Complex 1 and Modulates Redox Environment in Porcine Trophectoderm Cells

L-proline (proline) is a key regulator of embryogenesis, placental development, and fetal growth. However, the underlying mechanisms that support the beneficial effects of proline are largely unknown. This study used porcine trophectoderm cell line 2 (pTr2) to investigate the underlying mechanisms of proline in cell proliferation and redox homeostasis. Cells were cultured in the presence of 0, 0.25, 0.50, or 1.0 mmol/L proline for an indicated time. The results showed that 0.5 and 1.0 mmol/L proline enhanced cell viability. These effects of proline (0.5 mmol/L) were accompanied by the enhanced protein abundance of p-mTORC1, p-p70S6K, p-S6, and p-4E-BP1. Additionally, proline dose-dependently enhanced the mRNA expression of proline transporters [solute carrier family (SLC) 6A20, SLC36A1, SLC36A2, SLC38A1, and SLC38A2], elevated proline concentration, and protein abundance of proline dehydrogenase (PRODH). Furthermore, proline addition (0.25 or 0.5 mmol/L) resulted in lower abundance of p-AMPKα when compared with a control. Of note, proline resulted in lower reactive oxygen species (ROS) level, upregulated mRNA expression of the catalytic subunit of glutamate–cysteine ligase (GCLC) and glutathione synthetase (GSS), as well as enhanced total (T)-GSH and GSH concentration when compared with a control. These data indicated that proline activates themTORC1 signaling and modulates the intracellular redox environment via enhancing proline transport.

Role of astaxanthin as an efficient antioxidant on the in vitro maturation and vitrification of porcine oocytes

As one of the most powerful natural antioxidants, astaxanthin (Ax) has begun to be applied to the field of reproductive biology. Here we used porcine oocyte as a model to explore how Ax improves the oocyte potential during in vitro maturation (IVM), and we also investigated the cytoprotective effects of Ax on the vitrified oocytes. Ax supplementation (final concentration of 2.5 μM) was subjected for immature oocytes during vitrification and subsequent IVM; fresh oocytes were also matured in vitro in the presence or absence of 2.5 μM Ax. Our results showed that Ax significantly increased the survival rate of vitrified oocytes, and promoted the blastocyst yield of both fresh and vitrified oocytes after parthenogenetic activation and somatic cell nuclear transfer. The oocytes treated with Ax displayed significantly lower reactive oxygen species generation and higher glutathione level. Vitrification of oocytes had no impact on caspase-3, cathepsin B and autophagic activities; Ax significantly decreased the cathepsin B activity in both fresh and vitrified oocytes. Moreover, the relative fluorescence intensity of lysosomes was significantly increased in vitrified oocytes, which was recovered by Ax treatment. The mitochondrial activity did not differ between fresh and vitrified oocytes, and was significantly enhanced in Ax-treated oocytes. Furthermore, Ax significantly restored the decreased expression of BMP15, ZAR1, POU5F1, GPX4 and LAMP2 genes in vitrified oocytes. Both fresh and vitrified oocytes treated with Ax showed significantly higher mRNA levels of GDF9, POU5F1, SOD2, NRF2 and ATG5. Taken together, this study provides new perspectives in understanding the mechanisms by which Ax improves the developmental competence of both fresh and vitrified porcine oocytes.

Lycopene Improves In Vitro Development of Porcine Embryos by Reducing Oxidative Stress and Apoptosis

In vitro culture (IVC) for porcine embryo development is inferior compared to in vivo development because oxidative stress can be induced by the production of excessive reactive oxygen species (ROS) under high oxygen tension in the in vitro environment. To overcome this problem, we investigated the effect of lycopene, an antioxidant carotenoid, on developmental competence and the mechanisms involved in mitochondria-dependent apoptosis pathways in porcine embryos. In vitro fertilized (IVF) embryos were cultured in IVC medium supplemented with 0, 0.02, 0.05, 0.1, or 0.2 μM lycopene. The results indicate that 0.1 μM lycopene significantly increased the rate of blastocyst formation and the total cell numbers, including trophectoderm cell numbers, on Day In terms of mitochondria-dependent apoptosis, IVF embryos treated with 0.1 μM lycopene exhibited significantly decreased levels of ROS, increased mitochondrial membrane potential, and decreased expression of cytochrome c on Days 2 and Furthermore, 0.1 μM lycopene significantly decreased the number and percentage of caspase 3-positive and apoptotic cells in Day-6 blastocysts. In addition, Day-2 embryos and Day-6 blastocysts treated with 0.1 μM lycopene showed significantly reduced mRNA expression related to antioxidant enzymes (SOD1, SOD2, CATALASE) and apoptosis (BAX/BCL2L1 ratio). These results indicate that lycopene supplementation during the entire period of IVC enhanced embryonic development in pigs by regulating oxidative stress and mitochondria-dependent apoptosis.

A comparison of the effects of fetal bovine serum and newborn calf serum on cell growth and maintenance of cryopreserved mouse spermatogonial stem cells

Serum is a common supplement that is widely used to protect various cells and tissues from cryopreservation because it provides the necessary active components for cell growth and maintenance. In this study, we compared the effects of newborn calf serum (NCS) and fetal bovine serum (FBS) on the cryopreservation of mouse spermatogonial stem cells (SSCs). The isolated SSCs were cryopreserved in two groups: freezing medium that contained 10% DMSO (dimethyl sulfoxide) and 10% FBS in DMEM (Dulbecco's Modified Eagle's Medium) (group 1) and freezing medium that contained 10% DMSO and 10% NCS in DMEM (group 2). Real-time PCR was performed for stemness gene expression. The SSCs' viability was performed by trypan blue. We observed that the SSCs had increased viability in the NCS-freeze/thaw group (87.82%) compared to the FBS-freeze/thaw group (79.83%), but this increase was not statistically significant (P < 0.105). Promyelocytic leukemia zinc finger (Plzf) and Lin28 gene expression levels in the NCS-frozen/thawed SSCs were not significantly different compared to the FBS-frozen/thawed SSCs; however, Nanog gene expression increased considerably, and Dazl gene expression decreased significantly. The results in this study demonstrated that the presence of NCS in a solution of cryopreserved SSCs increased their viability after freeze/thawing and might promote the proliferation of cultivated SSCs in vitro by increasing the relative expression of Nanog.

Beneficial influence of fetal bovine serum on in vitro cryosurvival of chicken spermatozoa

Chicken spermatozoa are highly susceptible to cryopreservation often requiring extenders containing additives to enhance their post-thaw quality. Although protective properties of fetal bovine serum (FBS) during freezing of tissue cultured cells are widely known, its potential as a cryoprotectant for sperm cells has not been largely explored. Thus, the aims of our study were to (i) investigate the protective effect of FBS at different concentrations (0, 5, 10, 15 and 20%) against cryodamages in chicken spermatozoa, and (ii) test the FBS concentration that yielded the best preservation versus 1 mg/mL of cholesterol-loaded cyclodextrins (CLCs). Samples were assessed before and after freezing for sperm motility parameters, plasma membrane and acrosomal integrities, mitochondrial membrane potential, oxidative stress and plasma membrane peroxidation. Our findings showed that, despite their beneficial effects on fresh spermatozoa, higher FBS concentrations (15 and 20%) obtained the worst results for most motility and functional parameters after thawing. In contrast, lower FBS concentrations (5 and 10%) improved all post-thaw variables when compared to control. Afterwards, based on regression analysis, the concentration of 7% FBS was chosen to be assessed against CLCs in an experiment composed by four groups: control, FBS, CLCs, and FBS + CLCs. FBS and FBS + CLCs groups exhibited higher progressive motility in fresh samples, whereas only FBS maintained higher post-thaw progressive motility. Additionally, the incorporation FBS into extenders increased the percentage of rapid cells and reduced free radicals production and plasma membrane peroxidation. Together, these outcomes indicated that FBS minimize some harmful effects of cryopreservation, providing an alternative for chicken semen extenders that in many aspects appears to be superior to CLCs at 1 mg/mL.

Finegoldia magna, an Anaerobic Gram-Positive Bacterium of the Normal Human Microbiota, Induces Inflammation by Activating Neutrophils

The Gram-positive anaerobic commensal Finegoldia magna colonizes the skin and other non-sterile body surfaces, and is an important opportunistic pathogen. Here we analyzed the effect of F. magna on human primary neutrophils. F. magna strains ALB8 (expressing protein FAF), 312 (expressing protein L) and 505 (naturally lacking both protein FAF and L) as well as their associated proteins activate neutrophils to release reactive oxygen species, an indication for neutrophil oxidative burst. Co-incubation of neutrophils with the bacteria leads to a strong increase of CD66b surface expression, another indicator for neutrophil activation. Furthermore, all tested stimuli triggered the release of NETs from the activated neutrophils, pointing to a host defense mechanism in response to the tested stimuli. This phenotype is dependent on actin rearrangement, NADPH oxidases and the ERK1/2 pathway. Proteins FAF and L also induced the secretion of several pro-inflammatory neutrophil proteins; HBP, IL-8 and INFγ. This study shows for the first time a direct interaction of F. magna with human neutrophils and suggests that the activation of neutrophils plays a role in F. magna pathogenesis.

Embryo aggregation regulates in vitro stress conditions to promote developmental competence in pigs

Embryo aggregation is a useful method to produce blastocysts with high developmental competence to generate more offspring in various mammals, but the underlying mechanism(s) regarding the beneficial effects are largely unknown. In this study, we investigated the effects of embryo aggregation using 4-cell stage embryos in in vitro developmental competence and the relationship of stress conditions in porcine early embryogenesis. We conducted aggregation using the well of the well system and confirmed that aggregation using two or three embryos was useful for obtaining blastocysts. Aggregated embryos significantly improved developmental competence, including blastocyst formation rate, blastomere number, ICM/TE ratio, and cellular survival rate, compared to non-aggregated embryos. Investigation into the relationship between embryo aggregation and stress conditions revealed that mitochondrial function increased, and oxidative and endoplasmic reticulum (ER)-stress decreased compared to 1X (non-aggregated embryos) blastocysts. In addition, 3X (three-embryo aggregated) blastocysts increased the expression of pluripotency, anti-apoptosis, and implantation related genes, and decreased expression of pro-apoptosis related genes. Therefore, these findings indicate that embryo aggregation regulates in vitro stress conditions to increase developmental competence and contributes to the in vitro production of high-quality embryos and the large-scale production of transgenic and chimeric pigs.

Real-time PCR quantification of spliced X-box binding protein 1 (XBP1) using a universal primer method

X-box binding protein 1 (XBP1) mRNA processing plays a crucial role in the unfolded protein response (UPR), which is activated in response to endoplasmic reticulum (ER) stress. Upon accumulation of the UPR-converted XBP1 mRNA splicing from an unspliced (u) XBP1 (inactive) isoform to the spliced (s) XBP1 (active) isoform, inositol-requiring enzyme 1 α (IRE1α) removes a 26-nucleotide intron from uXBP1 mRNA. Recent studies have reported the assessment of ER stress by examining the ratio of sXBP1 to uXBP1 mRNA (s/uXBP1 ratio) via densitometric analysis of PCR bands relative to increased levels of sXBP1 to uXBP1 using a housekeeping gene for normalization. However, this measurement is visualized by gel electrophoresis, making it very difficult to quantify differences between the two XBP1 bands and complicating data interpretation. Moreover, most commonly used housekeeping genes display an unacceptably high variable expression pattern of the s/uXBP1 ratio under different experimental conditions, such as various phases of development and different cell types, limiting their use as internal controls. For a more quantitative determination of XBP1 splicing activity, we measured the expression levels of total XBP1 (tXBP1: common region of s/uXBP1) and sXBP1 via real-time PCR using specific primer sets. We also designed universal real-time PCR primer sets capable of amplifying a portion of each u/s/tXBP1 mRNA that is highly conserved in eukaryotes, including humans, monkeys, cows, pigs, and mice. Therefore, we provide a more convenient and easily approachable quantitative real-time PCR method that can be used in various research fields to assess ER stress.

Effect of Knockout Serum Replacement During Postwarming Recovery Culture on the Development and Quality of Vitrified Parthenogenetic Porcine Blastocysts

The postwarming recovery culture, as one of the steps in cryopreservation process, is directly correlated with the survival and quality of embryos. Generally, recovery medium includes undefined serum or serum components that may cause the instability of results and other problems. The objective of this study was to evaluate the effect of knockout serum replacement (KSR) as a substitute for serum during recovery culture on the development and quality of vitrified parthenogenetic porcine blastocysts. Fetal bovine serum (FBS) was used as a positive control. The expanded blastocysts on day 5 were vitrified by the Cryotop method, and recovered with 10% (v/v) KSR or 10% (v/v) FBS for 48 hours after warming. Survival and hatching rates of vitrified blastocysts were significantly increased by KSR or FBS supplementation. The vitrified blastocysts recovered in KSR or FBS exhibited significantly decreased percentages of membrane damage and apoptosis, and increased total cells. Addition of KSR or FBS during recovery culture significantly reduced reactive oxygen species levels, and improved mitochondrial activity and adenosine triphosphates content in the vitrified blastocysts. Vitrification did not affect the gene expression of PCNA, CDX2, and CPT1, but significantly increased mRNA levels of POU5F1 and uPA. KSR added to the recovery medium significantly upregulated mRNA levels of PCNA and CPT1, and downregulated POU5F1 mRNA levels. The expression levels of PCNA, CDX2, CPT1, and uPA in vitrified blastocysts were significantly upregulated by addition of FBS to recovery medium. Moreover, the BAX: BCL2L1 ratio was similar between fresh and vitrified blastocysts, and KSR or FBS supplementation had no effect on the value. In conclusion, our data showed that KSR supplementation during recovery culture can improve the development and quality of vitrified parthenogenetic porcine blastocysts. These findings provide a useful reference that KSR could be used to replace FBS as a defined serum supplement for recovery culture of vitrified blastocysts.

Feline embryo development in commercially available human media supplemented with fetal bovine serum

Feline embryo development was examined for 7 days after fertilization using commercially available human media supplemented with 0.3% bovine serum albumin (BSA) or 5% fetal bovine serum (FBS). Cumulus-oocyte complexes were categorized as Grades 1, 2, and 3 according to morphology. Only-One Medium (OM) was used for in vitro culture (IVC) in OM + BSA, OM + FBS, and OM + BSA/FBS, with BSA supplementation for the first 2 days and FBS for the subsequent 5 days. Embryos cultured in Early Culture Medium (1–2 days) and Blastocyst Medium (3–7 days) were defined as EB + BSA and EB + BSA/FBS. The developmental rate until the blastocyst stage of Grade 1 and 2 oocytes cultured in OM + BSA/FBS was higher than for the other groups and was significantly higher than for the OM + BSA and EB + BSA groups (P<0.01). Grade 3 oocytes cultured in OM + BSA/FBS also showed the greatest proportion of blastocyst formation. However, FBS supplementation throughout the IVC period reduced blastocyst number. The percentage of 2 pronuclei after fertilization as well as blastocyst cell number were significantly higher in Grade 1 and 2 than Grade 3 oocytes when cultured in OM + BSA/FBS (P<0.05). These results indicate that commercially available OM supplemented with BSA for the first 2 days of culture and FBS for the subsequent 5 days is suitable for feline embryo development until the blastocyst stage.

ROS-induced autophagy regulates porcine trophectoderm cell apoptosis, proliferation, and differentiation

Significant embryo loss remains a serious problem in pig production. Reactive oxygen species (ROS) play a critical role in embryonic implantation and placentation. However, the potential mechanism of ROS on porcine trophectoderm (pTr) cell fate during the peri-implantation period has not been investigated. This study aimed to elucidate the effects of ROS on pTr cell phenotypes and the regulatory role in cell attachment and differentiation. Herein, results showed that exogenous H₂O₂ inhibited pTr cell viability, arrested the cell cycle at S and G2/M phases, and increased cell apoptosis and autophagy protein light chain 3B and Beclin-1, whereas these effects were reversed by different concentrations of N-acetyl-l-cysteine (NAC) posttreatment. In addition, NAC abolished H₂O₂-induced autophagic flux, inhibited intracellular and mitochondrial ROS, and restored expression of genes important for mitochondrial DNA and biogenesis, cell attachment, and differentiation. NAC reversed H₂O₂-activated MAPK and Akt/mammalian target of rapamycin pathways in dose-dependent manners. Furthermore, analyses with pharmacological and RNA interference approaches suggested that autophagy regulated cell apoptosis and gene expression of caudal-related homeobox 2 and IL-1β. Collectively, these results provide new insights into the role of the ROS-induced autophagy in pTr cell apoptosis, attachment, and differentiation, indicating a promising target for decreasing porcine conceptus loss during the peri-implantation period.

Embryotropic effects of vascular endothelial growth factor on porcine embryos produced by in vitro fertilization

Current research suggests that supplementing in vitro culture (IVC) media with vascular endothelial growth factor (VEGF) may have beneficial effects on the development of porcine embryos in vitro. However, the molecular signaling mechanisms underlying this effect are unclear. Therefore, we aimed to investigate the effects of VEGF on molecular signaling events during in vitro embryonic development of porcine embryos. Porcine oocytes matured in vitro were fertilized, and the resultant zygotes were cultured with 5 ng/mL of VEGF supplemented with or without fetal bovine serum from day 4 till day 7. Without VEGF and/or FBS served as the control group. Real-time quantitative PCR was used to detect expression patterns of apoptosis- and oxidative stress-related genes in day 7 blastocysts (BLs). Early-stage apoptosis was detected by annexin-V assays in day 2 and day 7 embryos. We found that the addition of VEGF throughout the culture period with or without FBS supplementation significantly improved embryo survival and development. Supplementation with VEGF in the IVC medium significantly increased early BL formation (p < 0.05), although addition of FBS on day 4 significantly increased hatched BL formation (p < 0.05) regardless of VEGF supplementation. However, supplementation of media with both VEGF and FBS increased the formation of expanded BLs synergistically. The average total cell numbers per BL were significantly (p < 0.05) higher in embryos supplemented with VEGF and FBS than in those supplemented with either VEGF or FBS alone. We also found that accumulation of reactive oxygen species in VEGF-treated embryos was significantly lower (p < 0.05) than that in untreated embryos. The mRNA levels of caspase-3 were significantly lower (p < 0.05), and those of Bcl-2 and Nrf-2 were significantly higher (p < 0.05) in embryos grown in VEGF-supplemented media than in embryos grown in non-supplemented media. Furthermore, on day 2, the numbers of viable embryos (44.06 ± 3.94%) and blastomeres (67.18 ± 3.60%) were significantly higher (p < 0.05), and the numbers of early apoptotic embryos (55.94 ± 3.94) and blastomeres (23.23 ± 4.22) were significantly lower (p < 0.05) in VEGF-treated BLs than in controls. Furthermore, the numbers of early apoptotic cells in BLs on day 7 were also significantly lower (p < 0.05) in VEGF-treated BLs than in controls. Overall, our results indicate that supplementing IVC media with VEGF during in vitro culture of porcine embryos increases their developmental potential.

Oxidative degradation of polyamines by serum supplement causes cytotoxicity on cultured cells

Serum is a common supplement for cell culture due to it containing the essential active components for the growth and maintenance of cells. However, the knowledges of the active components in serum are incomplete. Apart from the direct influence of serum components on cultured cells, the reaction of serum components with tested drugs cannot be ignored, which usually results in the false conclusion on the activity of the tested drugs. Here we report the toxicity effect of polyamines (spermidine and spermine) on cultured cells, especially on drug-resistant cancer cell lines, which resulted from the oxidative degradation of polyamines by amine oxidases in serum supplement. Upon adding spermidine or spermine, high concentration of H₂O_2, an enzyme oxidation product of polyamines, was generated in culture media containing ruminant serum, such as fetal bovine serum (FBS), calf serum, bovine serum, goat serum or horse serum, but not in the media containing human serum. Drug-resistant cancer cell lines showed much higher sensitivity to the oxidation products of polyamines (H₂O₂ and acrolein) than their wild cell lines, which was due to their low antioxidative capacity.

Mito-TEMPO improves development competence by reducing superoxide in preimplantation porcine embryos

Mito-TEMPO is a well-known mitochondria-specific superoxide scavenger. However, the effect of Mito-TEMPO on porcine embryo development, to our knowledge, has not been studied yet. In the present study, porcine embryos were classified into two groups (G1 and G2) based on the cytoplasm lipid contents at the zygote stage. The development of blastocysts derived from G2 zygotes was reduced (G2:16.2 ± 7.9% vs G1: 26.5 ± 5.9%; 1.6-fold, p < 0.05) compared to those from G1 zygotes. In G2 embryos, the proportion of TUNEL-positive cells was also higher than that of G1 embryos. Superoxide in G2 embryos was significantly increased compared to that in G1 embryos. Mitochondrial membrane potential and ATP production were lower in G2 embryos than in G1 embryos. Phosphorylation of Drp1 at Ser 616 increased in G1 embryos during the cleavage stages compared to that in the zygote but was not significantly different in G2 embryos. Then, the effects of Mito-TEMPO were investigated in G2 embryos. Blastocyst formation rate (G2: 19.1 ± 5.1% vs G2 + Mito-TEMPO: 28.8 ± 4.0%; 1.5-fold, p < 0.05) and mitochondrial aggregation were recovered after superoxide reduction by Mito-TEMPO treatment. Thus, we showed that Mito-TEMPO improves blastocyst development by superoxide reduction in porcine embryos in vitro.

Glucocorticoids induce apoptosis and matrix metalloproteinase-13 expression in chondrocytes through the NOX4/ROS/p38 MAPK pathway

Based on the results from our previous study, dexamethasone (Dex) increases reactive oxygen species (ROS) levels and subsequently induces cell death and matrix catabolism in chondrocytes. Nevertheless, the mechanism underlying this phenomenon remains unclear. Nicotinamide adenine dinucleotide (phosphate) (NADPH) oxidase 4 (NOX4) is one of the major enzymes responsible for intracellular ROS production during the inflammatory process. The objective of the current study was to investigate the role of NOX4 in Dex-induced ROS over-production. Healthy chondrocytes were harvested from the cartilage debris from 6 female patients. NOX4 and p38 mitogen-activated protein kinase (MAPK) expression levels in these cells were evaluated in the presence of Dex. Changes in the number of apoptotic and viable Dex-treated chondrocytes were recorded after the cells were treated with NOX and p38 MAPK inhibitors. Changes in matrix metalloproteinase 13 (MMP-13) expression levels in Dex-treated chondrocytes were also investigated. The Dex treatment increased NOX4 expression via the glucocorticoid receptor (GR). Treatment of cells with apocynin, a NOX inhibitor, decreased intracellular ROS levels and inhibited p38 MAPK activation. Treatment of cells with a ROS scavenger also reduced p38 MAPK expression. Treatment of cells with a NOX inhibitor, ROS scavenger and p38 MAPK inhibitor rescued chondrocytes from Dex-induced apoptosis. Moreover, treatment of cells with these agents blocked MMP-13 expression in Dex-treated chondrocytes. NOX4 silencing also suppressed p38 MAPK and MMP-13 expression. Dex triggered apoptosis and MMP-13 expression through the NOX4/ROS/p38 MAPK signaling pathway. NOX4 may be a therapeutic target in the management of Dex-induced complications.