Effects of MICU1-Mediated Mitochondrial Calcium Uptake on Energy Metabolism and Quality of Vitrified-Thawed Mouse Metaphase II Oocytes

Background: Oocyte vitrification has been widely used in the treatment of infertility and fertility preservation. However, vitrification-induced mitochondrial damage adversely affects oocyte development. Several studies have reported that mitochondrial calcium uptake protein 1 (MICU1) regulates the uptake of mitochondrial calcium by the mitochondrial calcium uniporter (MCU) and subsequently controls aerobic metabolism and oxidative stress in mitochondria, but research considering oocytes remains unreported. We evaluated whether the addition of MICU1 modulators enhances mitochondrial activity, pyruvate metabolism, and developmental competence after warming of MII oocytes. Methods: Retrieved MII oocytes of mice were classified as vitrified or control groups. After thawing, oocytes of vitrified group were cultured with or without DS16570511 (MICU1 inhibitor) and MCU-i4 (MICU1 activator) for 2 h. Results: Mitochondrial Ca²⁺ concentration, pyruvate dephosphorylation level, and MICU1 expression of MII oocytes were significantly increased after vitrification. These phenomena were further exacerbated by the addition of MCU-i4 and reversed by the addition of DS16570511 after warming. However, the mitochondrial membrane potential (MMP) and adenosine triphosphate (ATP) in vitrified-warmed MII oocytes drop significantly after vitrification, which was improved after MCU-i4 treatment and decreased significantly after DS16570511 treatment. The vitrification process was able to elicit a development competence reduction. After parthenogenetic activation, incubation of the thawed oocytes with MCU-i4 did not alter the cleavage and blastocyst rates. Moreover, incubation of the thawed oocytes with DS16570511 reduced the cleavage and blastocyst rates. Conclusions: MICU1-mediated increasing mitochondrial calcium uptake after vitrification of the MII oocytes promoted the pyruvate oxidation, and this process may maintain oocyte development competence by compensating for the consumption of ATP under stress state.     

Non-equilibrium processes in poly(vinyl chloride) glasses vitrified at elevated pressures

The conformational and enthalpic changes that occur in poly(vinyl chloride) (PVC) glasses that have been vitrified from the melt under pressure have been examined by Fourier transform infrared spectroscopy and quantitative differential scanning calorimetry. It is shown that these pressures freeze in the high energy states that are characteristic of the vitrification temperature and increase the apparent glass transition temperature of the polymer. In addition, pressures in excess of the vitrification pressure, cause intermolecular effects that can be relaxed out below T_g. Both of these processes create characteristic endothermic and exothermic changes in the apparent heat capacity of the glass that appear over a period of time and are sensitive functions of the glass formation. processes as well as the subsequent annealing history. The endothermic events are interpreted as the stress perturbed volumetric relaxation process while the exotherms are associated with the release of the frozen in stresses.     

Non-equilibrium processes in poly(vinyl chloride) glasses vitrified at elevated pressures

The conformational and enthalpic changes that occur in poly(vinyl chloride) (PVC) glasses that have been vitrified from the melt under pressure have been examined by Fourier transform infrared spectroscopy and quantitative differential scanning calorimetry. It is shown that these pressures freeze in the high energy states that are characteristic of the vitrification temperature and increase the apparent glass transition temperature of the polymer. In addition, pressures in excess of the vitrification pressure, cause intermolecular effects that can be relaxed out below T_g. Both of these processes create characteristic endothermic and exothermic changes in the apparent heat capacity of the glass that appear over a period of time and are sensitive functions of the glass formation processes as well as the subsequent annealing history. The endothermic events are interpreted as the stress perturbed volumetric relaxation process white the exotherms are associated withh the release of the frozen in stresses.     

Overexpression of ERAP2N in Human Trophoblast Cells Promotes Cell Death

The genes involved in implantation and placentation are tightly regulated to ensure a healthy pregnancy. The endoplasmic reticulum aminopeptidase 2 (ERAP2) gene is associated with preeclampsia (PE). Our studies have determined that an isoform of ERAP2-arginine (N), expressed in trophoblast cells (TC), significantly activates immune cells, and ERAP2N-expressing TCs are preferentially killed by both cytotoxic T lymphocytes (CTLs) and Natural Killer cells (NKCs). To understand the cause of this phenomenon, we surveyed differentially expressed genes (DEGs) between ERAP2N expressing and non-expressing TCs. Our RNAseq data revealed 581 total DEGs between the two groups. 289 genes were up-regulated, and 292 genes were down-regulated. Interestingly, most of the down-regulated genes of significance were pro-survival genes that play a crucial role in cell survival (LDHA, EGLN1, HLA-C, ITGB5, WNT7A, FN1). However, the down-regulation of these genes in ERAP2N-expressing TCs translates into a propensity for cell death. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that 64 DEGs were significantly enriched in nine pathways, including “Protein processing in endoplasmic reticulum” and “Antigen processing and presentation”, suggesting that the genes may be associated with peptide processes involved in immune recognition during the reproductive cycle.     

Conversion analysis of acrylated hyperbranched polymers UV‐cured below their ultimate glass transition temperature

The photo‐curing behavior of reactive blends of dipentaerythritol penta/hexaacrylate (DPHA) with an acrylated hyperbranched polyester and an acrylated hyperbranched polyether was investigated by means of photo differential scanning calorimetry. The chemical conversion data was analyzed using an autocatalytic model with close attention paid to the influence of composition, UV intensity, and vitrification. The autocatalytic model was found to be relevant to describe autoacceleration and diffusion controlled reaction stages, as long as the polymers were not vitrified. It was shown that the reaction order and the autocatalytic exponent were independent of UV intensity, whereas the rate constant showed strong intensity dependence, and the maximal conversion showed weak intensity dependence. A criterion for vitrification onset was proposed as the occurrence of a third stage in the conversion process. The ultimate conversion was found to be 0.16 higher than the conversion at vitrification for all investigated multifunctional acrylates independent of composition and UV intensity. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2366–2376, 2007     

Hydration reactions of cement combinations containing vitrified incinerator fly ash

One treatment option for municipal solid waste incinerator fly ash (IFA) is vitrification. The process yields a material containing reduced levels of trace metals relative to the original ash. The material is glassy and potentially suitable as a cement component in concrete. This paper examines the vitrification of an IFA and studies the hydration reactions of combinations of this vitrified material and Portland cement (PC). Isothermal conduction calorimetry, powder X-ray diffraction (XRD), thermogravimetry (TG) and scanning electron microscopy were employed to study the hydration reactions. As the levels of vitrified ash increase, the quantities of AFt phase produced decrease, whilst quantities of AFm phase increase, due to the reduced levels of sulfate in the vitrified ash. The levels of calcium silicate hydrate (CSH) gel (inferred from estimates of quantities of gel-bound water) remain constant at 28 days regardless of vitrified ash content, indicating that the material is contributing toward the formation of this product.     

Transcriptome Analysis Revealed the Embryo-Induced Gene Expression Patterns in the Endometrium from Meishan and Yorkshire Pigs

The expression patterns in Meishan- and Yorkshire-derived endometrium during early (gestational day 15) and mid-gestation (gestational days 26 and 50) were investigated, respectively. Totally, 689 and 1649 annotated genes were identified to be differentially expressed in Meishan and Yorkshire endometrium during the three gestational stages, respectively. Hierarchical clustering analysis identified that, of the annotated differentially expressed genes (DEGs), 73 DEGs were unique to Meishan endometrium, 536 DEGs were unique to Yorkshire endometrium, and 228 DEGs were common in Meishan and Yorkshire endometriums. Subsequently, DEGs in each of the three types of expression patterns were grouped into four distinct categories according to the similarities in their temporal expression patterns. The expression patterns identified from the microarray analysis were validated by quantitative RT-PCR. The functional enrichment analysis revealed that the common DEGs were enriched in pathways of steroid metabolic process and regulation of retinoic acid receptor signaling. These unique DEGs in Meishan endometrium were involved in cell cycle and adherens junction. The DEGs unique to Yorkshire endometrium were associated with regulation of Rho protein signal transduction, maternal placenta development and cell proliferation. This study revealed the different gene expression patterns or pathways related to the endometrium remodeling in Meishan and Yorkshire pigs, respectively. These unique DEGs in either Meishan or Yorkshire endometriums may contribute to the divergence of the endometrium environment in the two pig breeds.     

Spermatozoan Metabolism as a Non-Traditional Model for the Study of Huntington’s Disease

Huntington’s Disease (HD) is a fatal autosomal dominant neurodegenerative disease manifested through motor dysfunction and cognitive deficits. Decreased fertility is also observed in HD animal models and HD male patients, due to altered spermatogenesis and sperm function, thus resulting in reduced fertilization potential. Although some pharmaceuticals are currently utilized to mitigate HD symptoms, an effective treatment that remedies the pathogenesis of the disease is yet to be approved by the FDA. Identification of genes and relevant diagnostic biomarkers and therapeutic target pathways including glycolysis and mitochondrial complex-I-dependent respiration may be advantageous for early diagnosis, management, and treatment of the disease. This review addresses the HD pathway in neuronal and sperm metabolism, including relevant gene and protein expression in both neurons and spermatozoa, indicated in the pathogenesis of HD. Furthermore, zinc-containing and zinc-interacting proteins regulate and/or are regulated by zinc ion homeostasis in both neurons and spermatozoa. Therefore, this review also aims to explore the comparative role of zinc in both neuronal and sperm function. Ongoing studies aim to characterize the products of genes implicated in HD pathogenesis that are expressed in both neurons and spermatozoa to facilitate studies of future treatment avenues in HD and HD-related male infertility. The emerging link between zinc homeostasis and the HD pathway could lead to new treatments and diagnostic methods linking genetic sperm defects with somatic comorbidities.     

Protective Strategies of Haberlea rhodopensis for Acquisition of Freezing Tolerance: Interaction between Dehydration and Low Temperature

Resurrection plants are able to deal with complete dehydration of their leaves and then recover normal metabolic activity after rehydration. Only a few resurrection species are exposed to freezing temperatures in their natural environments, making them interesting models to study the key metabolic adjustments of freezing tolerances. Here, we investigate the effect of cold and freezing temperatures on physiological and biochemical changes in the leaves of Haberlea rhodopensis under natural and controlled environmental conditions. Our data shows that leaf water content affects its thermodynamical properties during vitrification under low temperatures. The changes in membrane lipid composition, accumulation of sugars, and synthesis of stress-induced proteins were significantly activated during the adaptation of H. rhodopensis to both cold and freezing temperatures. In particular, the freezing tolerance of H. rhodopensis relies on a sucrose/hexoses ratio in favor of hexoses during cold acclimation, while there is a shift in favor of sucrose upon exposure to freezing temperatures, especially evident when leaf desiccation is relevant. This pattern was paralleled by an elevated ratio of unsaturated/saturated fatty acids and significant quantitative and compositional changes in stress-induced proteins, namely dehydrins and early light-induced proteins (ELIPs). Taken together, our data indicate that common responses of H. rhodopensis plants to low temperature and desiccation involve the accumulation of sugars and upregulation of dehydrins/ELIP protein expression. Further studies on the molecular mechanisms underlying freezing tolerance (genes and genetic regulatory mechanisms) may help breeders to improve the resistance of crop plants.     

Real-time dielectric studies of network formation in thermally activated epoxy-amine and isocyanate-triol systems

Dielectric measurements are reported on the changes that occur in the nature of the dipole relaxation processes during cure of an epoxy-amine and a diisocyanate-triol system. The epoxy resin forms a vitrified solid in the final cured state, whereas the urethane retains its elastomeric properties. The initial behaviour for the epoxy resin is dominated by ionic conduction processes. Subtraction of the conductivity contribution reveals a dipolar relaxation process, which is analysed using the Havriliak-Negami (HN) equation. The characteristic exponent 1 - n of the HN equation changes in a similar manner to that found with other epoxy-amine systems. However, the dipolar process in the urethane occurs at very high frequency and a different form of the 1 - n dependence is observed. Sensitivity of the dielectric method for the detection of vitrification and gelation is critically assessed. If the vitrification is allowed to occur, then detection of a gel point may not necessarily be inferred from the dielectric data.     

Identification of a Tumor Cell Associated Type I IFN Resistance Gene Expression Signature of Human Melanoma,the Components of Which Have a Predictive Potential for Immunotherapy

We developed a human melanoma model using the HT168-M1 cell line to induce IFN-α2 resistance in vitro (HT168-M1res), which was proven to be maintained in vivo in SCID mice. Comparing the mRNA profile of in vitro cultured HT168-M1res cells to its sensitive counterpart, we found 79 differentially expressed genes (DEGs). We found that only a 13-gene core of the DEGs was stable in vitro and only a 4-gene core was stable in vivo. Using an in silico cohort of IFN-treated melanoma tissues, we validated a differentially expressed 9-gene core of the DEGs. Furthermore, using an in silico cohort of immune checkpoint inhibitor (ICI)-treated melanoma tissues, we tested the predictive power of the DEGs for the response rate. Analysis of the top four upregulated and top four downregulated genes of the DEGs identified WFDC1, EFNA3, DDX10, and PTBP1 as predictive genes, and analysis of the “stable” genes of DEGs for predictive potential of ICI response revealed another 13 genes, out of which CDCA4, SOX4, DEK, and HSPA1B were identified as IFN-regulated genes. Interestingly, the IFN treatment associated genes and the ICI-therapy predictive genes overlapped by three genes: WFDC1, BCAN, and MT2A, suggesting a connection between the two biological processes.