The PPARδ Agonist GW501516 Improves Lipolytic/Lipogenic Balance through CPT1 and PEPCK during the Development of Pre-Implantation Bovine Embryos

Short-Chain Fatty Acids (SCFAs) Modulate the Hepatic Glucose and Lipid Metabolism of Coilia nasus via the FFAR/AMPK Signaling Pathway In Vitro

The expansion of intensive aquaculture has heightened metabolic dysregulation in fish caused by high-glucose and high-lipid (HG-HL) diets, contributing to growth retardation and hepatic pathologies. Using Coilia nasus hepatocytes, this study investigated the regulatory effects of short-chain fatty acids (SCFAs) on glucose-lipid metabolism. In vitro HG-HL exposure elevated intracellular glucose, triglycerides (TG), and cholesterol; suppressed catalase (CAT) and superoxide dismutase (SOD); and dysregulated metabolic genes (upregulated phosphoenolpyruvate carboxykinase and acetyl-CoA carboxylase; downregulated glucokinase and hormone-sensitive lipase). Co-treatment with acetate and propionate reversed these anomalies, reducing TG and cholesterol, restoring antioxidant capacity (SOD and CAT), and normalizing gene expression patterns. Molecular docking suggested potential binding interactions between SCFAs and free fatty acid receptor (FFAR2/3). This study provided initial evidence suggesting SCFAs might attenuate HG-HL-induced metabolic stress in a teleost model, potentially involving FFAR-related pathways and AMPK-associated responses. The findings contribute to understanding SCFA-mediated metabolic regulation in fish, offering preliminary support for developing dietary interventions to manage aquacultural metabolic syndromes.

Beta-aminoisobutyric acid improves bovine oocyte maturation and subsequent embryonic development by promoting lipid catabolism

Energy metabolism homeostasis is essential for oocyte maturation and acquisition of developmental capacity. However, bovine oocyte in vitro maturation (IVM) is highly susceptible to metabolic stress and lipid accumulation. β-Aminoisobutyric acid (BAIBA), a metabolite produced in response to skeletal muscle exercise, has been reported to be involved in lipid and glucose metabolism, as well as inflammation and oxidative stress. This work aimed to evaluate the potential effects of BAIBA on bovine oocyte IVM and its mechanisms. Different concentrations of BAIBA (10, 20, 50, 100, and 200 μmol/L) were supplemented to bovine oocyte IVM medium. Results shown the BAIBA (50 μmol/L) had no effect on the extrusion rate of the first polar body of oocytes but significantly improved the subsequent blastocyst formation rate and embryo quality. Further revealed that supplementing BAIBA significantly up-regulated expression levels of genes to fatty acid β-oxidation metabolism (CPT1A, CPT1B and CPT2), promoted lipid metabolism, lowered lipid content, and improved mitochondrial membrane potential and active mitochondria content. Importantly, BAIBA stimulation significantly increased the phosphorylation of AMP-activated protein kinase (AMPK); and the inhibition of AMPK activity (Compound C, AMPK inhibitor) suppressed the ability of BAIBA to promote lipid metabolism in oocytes. Besides, inhibition of AMPK lowered the oocyte maturation rate and the subsequent zygote cleavage and blastocyst formation rate when compared to that of the BAIBA treatment. The results indicated that BAIBA was mainly involved in promoting lipid catabolism by activation of AMPK, consequently enhancing oocyte development potential.

PPARGC1A regulates transcriptional control of mitochondrial biogenesis in early bovine embryos

Extensive mitochondrial replication during oogenesis and its role in oocyte maturation and fertilization indicate that the amount of mitochondrial DNA (mtDNA) may play a significant role in early embryonic development. Early embryos express peroxisome proliferator-activated receptor gamma co-activator alpha (PPARGC1A/PGC-1a), a protein essential for mitochondrial biogenesis. This study investigated the role of PGC-1α from a single-cell zygotic stage to day-8 bovine blastocyst and the effect of PGC-1a knockdown (KD) on embryo mitochondria and development. PGC-1α KD via siRNA injection into single-cell zygotes does not substantially affect embryonic cleavage up to the morula stage but considerably reduces blastocyst development (18.42%) and hatching than the control (32.81%). PGC-1α regulates transcription of the gene encoding mitochondrial transcription factor A (TFAM), and immunofluorescence analysis indicated significantly lower TFAM expression in the 16-cell KD embryos and day-8 KD blastocysts. Reduction in NRF1 protein's nuclear localization in bovine blastomeres was also observed in PGC-1α-KD embryos. Furthermore, to understand the effect of PGC-1α-KD on the mitochondrial genome, we found a low mtDNA copy number in PGC-1α-KD day-8 bovine blastocysts. Several genes related to mitochondrial functioning, like ND1, ND3, ND5, ATPase8, COI, COII, and CYTB, were significantly downregulated in PGC-1α-KD embryos. Moreover, high mitochondrial depolarization (ΔΨm) and abnormal lipid depositions were observed in the PGC-1α KD blastocysts. SIRT1 is the upstream regulator of PGC-1α, but SIRT1 activation via Hesperetin does not affect PGC-1α-KD embryonic development considerably. In conclusion, PGC-1α plays a critical role in early embryo mitochondrial functioning, and any perturbation in its expression significantly disrupts early embryonic development.

Transcriptomics and metabolomics insights into the seasonal dynamics of meat quality in yak on the Qinghai-Tibetan Plateau

BACKGROUND

Meat quality in yak is influenced by the fluctuation of nutritional composition in different grazing seasons on the Qinghai-Tibetan Plateau. However, the molecular mechanism underlying in yak meat remains unknown. Therefore, this study aimed to investigate the seasonal dynamics of meat quality in yak by transcriptomics and metabolomics techniques. Twelve healthy female yaks with a similar weight were divided into two groups, including the warm season group (WS) and cold season group (CS). After slaughter, samples of longissimus lumborum were collected and subjected to transcriptomics and metabolomics to explore the effects of different seasons on meat quality.

RESULTS

Yak in the WS group had higher contents of n-3 Polyunsaturated fatty acid (PUFA), n-6 PUFA, threonine, and valine compared to the CS group, but the pH45min and b* values were lower. A total of 75 differentially expressed metabolites in the longissimus lumborum muscle were identified, with 23 metabolites upregulated and 52 metabolites downregulated in the WS group. These metabolites were mainly enriched in the pathway of glycine, serine and threonine metabolism, tryptophan metabolism, and carbohydrate digestion and absorption. In comparison, the WS group exhibited 262 upregulated genes in the longissimus lumborum muscle and 81 downregulated genes relatives to the CS group, which were enriched in the fat deposition of TGF-beta, ECM-receptor interaction, MAPK, and PPAR signaling pathway.

CONCLUSIONS

Among these, downregulated genes NPNT, GADL1, SESN3, and CPXM1 were associated with lipid metabolism and fat deposition in grazing yaks. It was found that DDC, DHTKD1, CCBL1, GCDH, and AOC1 involved in the tryptophan metabolism played an important role in the regulation of energy metabolism in yak.

Probiotics Enhance Coilia nasus Growth Performance and Nutritional Value by Regulating Glucolipid Metabolism via the Gut-Liver Axis

Large-scale intensive feeding triggered reduced growth performance and nutritional value. Exogenous probiotics can promote the growth performance and nutritional value of fish through improving the intestinal microbiota. However, detailed research on the correlation between the intestinal microbiota, growth performance, and nutritional value remains to be elucidated. Therefore, we performed metagenomic and metabolomic analysis to investigate the effects of probiotic addition to basal diet (1.0 × 108 CFU/g) (PF) and water (1.0 × 108 CFU/g) (PW) on the growth performance, muscle nutritional value, intestinal microbiota and their metabolites, and glucolipid metabolism in Coilia nasus. The results showed that FBW, BL, and SGR were enhanced in PF and PW groups. The concentrations of EAAs, TAAs, SFAs, MUFAs, and PUFAs were increased in PF and PW groups. Metagenomic and metabolic analyses revealed that bacterial community structure and metabolism were changed in the PF and PW groups. Moreover, adding probiotics to diet and water increased SCFAs and bile acids in the intestine. The gene expression associated with lipolysis and oxidation (hsl, pparα, cpt1, and acadm) and glycolysis (gck and pfk) was upregulated, while the gene expression associated with lipid synthesis (srebp1, acc, dgat, and elovl6) and gluconeogenesis (g6pca1, g6pca2, and pck) was downregulated in the liver. Correlation analysis displayed that hepatic glucolipid metabolism was regulated through the microbiota-gut-liver axis. Mantel test analysis showed that growth performance and muscle nutritional value were improved by the gut-liver axis. Our findings offered novel insights into the mechanisms that underlie the enhancement of growth performance and nutritional value in C. nasus and other fish by adding probiotics.

Molecular characterization and transcriptional regulation between PPAR and CPT1 in freshwater bivalve Hyriopsis cumingii

Peroxisome proliferator activated receptors (PPARs) exert their roles in lipid metabolism and adaptive immunity by transactivating carnitine palmitoyltransferase 1 (CPT1). However, it remains unclear whether the PPAR-CPT1 signaling pathway exists in mollusks that only carry out innate immunity. This study cloned and characterized PPAR and CPT1 genes from Hyriopsis cumingii for the first time, designated as HcPPARs and HcCPT1s, respectively. The bioinformatics analysis revealed conservative molecular characteristics of these genes across species. Real-time quantitative PCR results indicated that higher expression levels of HcPPARs and HcCPT1s in the blood, mantle, and intestine suggested their potential involvement in lipid metabolism and innate immunity of mollusks. Treatments with agonists and inhibitors demonstrated a correlation in the expression of HcPPARs and HcCPT1s. Dual luciferase reporter assay identified regions with high transcriptional activities on promoters of HcCPT1s and potential binding sites for HcPPARs through prediction and mutation sites. These results suggested that the PPAR-CPT1 signaling might exist in H. cumingii. This research provides a necessary foundation for exploring the role of the PPAR-CPT1 signaling in innate immunity, and offers new theoretical evidence for the molecular regulatory mechanism of mollusks and the treatment of metabolic disorders and inflammatory diseases.

Chemically programmed metabolism drives a superior cell fitness for cartilage regeneration

The rapid advancement of cell therapies underscores the importance of understanding fundamental cellular attributes. Among these, cell fitness-how transplanted cells adapt to new microenvironments and maintain functional stability in vivo-is crucial. This study identifies a chemical compound, FPH2, that enhances the fitness of human chondrocytes and the repair of articular cartilage, which is typically nonregenerative. Through drug screening, FPH2 was shown to broadly improve cell performance, especially in maintaining chondrocyte phenotype and enhancing migration. Single-cell transcriptomics indicated that FPH2 induced a super-fit cell state. The mechanism primarily involves the inhibition of carnitine palmitoyl transferase I and the optimization of metabolic homeostasis. In animal models, FPH2-treated human chondrocytes substantially improved cartilage regeneration, demonstrating well-integrated tissue interfaces in rats. In addition, an acellular FPH2-loaded hydrogel proved effective in preventing the onset of osteoarthritis. This research provides a viable and safe method to enhance chondrocyte fitness, offering insights into the self-regulatory mechanisms of cell fitness.

Developmental toxicity and potential mechanisms exposed to polystyrene microplastics and polybrominated diphenyl ethers during early life stages of fat greenling (Hexagrammos otakii)

The occurrence of microplastics (MPs) in aquatic ecosystems and their ability to absorb hydrophobic pollutants, such as persistent organic pollutants (POPs), is currently a significant concern. MPs, which are the main breakdown product of plastics, have been frequently detected in the environment, posing serious threats to organisms' health. One particular pollutant, 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), is a dominant congener of PBDEs and is highly toxic to organisms. However, there is limited knowledge regarding the exposure of marine fishes to PBDEs through MPs and their combined toxic effects. In this study, the embryo toxicity of Hexagrammos otakii was conducted to investigate the combined effects of MPs and BDE-47. The results showed that MPs and BDE-47 co-exposure had detrimental effects on embryonic development, such as reduced hatchability, increased mortality, decreased heart rate, and body malformation. Moreover, the combined toxicity of these substances appeared more pronounced harmful effects compared to exposure to BDE-47 alone. Histopathological examination revealed that co-exposure can cause greater damage to hatching glands and yolk. The enrichment of Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways included phagosome, metabolism of xenobiotics by cytochrome P450, TCA cycle, and Wnt signaling pathway, which are closely related to embryonic growth. BDE-47 and MPs may activate the Wnt signaling pathway to affect the normal development of embryos. Our results suggest that MPs and BDE-47 exposure may cause growth disorders in the early life stages of H.otakii, leading to abnormal embryonic development. All these results will contribute to the further study of the ecological risk assessment and toxicity of MPs and organic pollutant mixtures in marine fish.

Effect of additional cytoplasm injection on the cloned bovine embryo organelle distribution and stress mitigation

Although somatic cell nuclear transfer (SCNT) is a critical component of animal cloning, this approach has several issues. We previously introduced the cytoplasm injection cloning technology (CICT), which significantly improves the quality and quantity of cloned embryos. This study examined the residual status of fused cytoplasmic organelles, such as the endoplasmic reticulum (ER) and lysosomes, in the CICT group during early embryo development. We found that extra-cytoplasmic organelles stained using the ER-Tracker™ Green dye and LysoTracker™ Deep Red probe were fused and dispersed throughout the recipient oocyte and were still visible in day 8 blastocysts. We screened for ER stress, autophagy, and apoptosis-related genes to elucidate the association between the added organelles and improved embryo quality in CICT-cloned embryos. We found that CHOP, ATF4, ATG5, ATG7, and LC3 genes showed non-significantly up- or downregulated expression between CICT- and in vitro fertilization (IVF)-derived embryos but showed significantly (p < 0.05) upregulated expression in SCNT-cloned embryos. Surprisingly, a non-significant difference in the expression of some genes, such as ATF6 and caspase-3, was observed between the CICT- and SCNT-cloned embryos. Our findings imply that compared to conventional SCNT cloning, CICT-derived cloned embryos with additional cytoplasm have much higher organelle activity, lower autophagy, lower rates of apoptosis, and higher embryo development rates.

Dynamic Changes in Proteome during Yak Oocyte Maturation Analyzed Using iTRAQ Technology

The aim of this study was to investigate protein regulation at different time points during the in vitro maturation of yak oocytes. Yak oocytes at GV, MI, and MII stages were collected during in vitro maturation, and differential proteomics sequencing was performed using iTRAQ technology. GO functional classification indicated that the differential proteins were closely associated with biological processes such as "metabolic processes", and molecular events such as "binding" molecular-function-related categories were active. KOG analysis showed that energy-metabolism-related activities were vigorous during oocyte development from the GV phase to MI phase, and genetic material preparation activities were more active when oocytes developed from the MI stage to MII stage. KEGG pathway analysis showed that the PPAR metabolic pathway, Hippo signaling pathway, and ECM-receptor interaction and metabolic pathway were enriched from the GV to the MI stages. The PI3K-Akt, TGF-β, and phagosome pathways were enriched from the MI stage to the MII stage. These results indicate that transient dynamic changes occurred in the proteome during the maturation of yak oocytes, and the physiological functions mediated by these were also different. The accurate identification of the differential proteins in the three stages of GV, MI, and MII was helpful in further analyzing the molecular regulatory mechanism of yak oocyte maturation.

Targeting PPARs for therapy of atherosclerosis: A review

Atherosclerosis, a chief pathogenic factor of cardiovascular disease, is associated with many factors including inflammation, dyslipidemia, and oxidative stress. Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors and are widely expressed with tissue- and cell-specificity. They control multiple genes that are involved in lipid metabolism, inflammatory response, and redox homeostasis. Given the diverse biological functions of PPARs, they have been extensively studied since their discovery in 1990s. Although controversies exist, accumulating evidence have demonstrated that PPAR activation attenuates atherosclerosis. Recent advances are valuable for understanding the mechanisms of action of PPAR activation. This article reviews the recent findings, mainly from the year of 2018 to present, including endogenous molecules in regulation of PPARs, roles of PPARs in atherosclerosis by focusing on lipid metabolism, inflammation, and oxidative stress, and synthesized PPAR modulators. This article provides information valuable for researchers in the field of basic cardiovascular research, for pharmacologists that are interested in developing novel PPAR agonists and antagonists with lower side effects as well as for clinicians.

Whole body vibration activates AMPK/CPT1 signaling pathway of skeletal muscle in young and aging mice based on metabolomics study

Whole-body vibration (WBV) can improve skeletal muscle function in aging mice, but whether the effect on young and aging skeletal muscle is consistent has not been studied. We selected C57BL/6J mouse models, which were divided into young control group (YC), young vibration group (YV), aging control group (AC) and aging vibration group (AV). After 12 weeks of WBV, we found that compared with the YC group, the pathways of linoleic acid metabolism, biosynthesis of unsaturated fatty acids, arachidonic acid metabolism, nicotinate and nicotinamide metabolism, glycine, serine and threonine metabolism, and arginine and proline metabolism improved significantly in the YV group. Compared with the AC group, the pathways of arachidonic acid metabolism, alpha-linolenic acid metabolism, biosynthesis of unsaturated fatty acids, pentose and glucuronate interconversions and pentose phosphate pathway improved significantly in the AV group. Furthermore, we found that WBV decreased triglyceride (TG), total cholesterol (TC), and free fatty acid (FFA) levels in aging mice, improved mitochondrial membrane potential, and increased the expression of phosphorylated activated protein kinase (p-AMPK), peroxisome proliferator-activated receptor coactivator-1α (PGC-1α) and carnitine palmitoyl transferase 1B (CPT1B) in the skeletal muscle of young and aging mice. Our study revealed that WBV mainly improved lipid metabolism and amino acid metabolism pathways of skeletal muscle in young mice and mainly improved lipid metabolism and glucose metabolism pathways of skeletal muscle in aging mice. WBV can activate the AMPK/CPT1 signaling pathway and improve mitochondrial function in skeletal muscle in both young and aging mice.

BOEC–Exo Addition Promotes In Vitro Maturation of Bovine Oocyte and Enhances the Developmental Competence of Early Embryos

Simple Summary

The results of the present study proved that the addition of bovine oviductal epithelial cell derived exosomes (BOEC–Exo) to the in vitro maturation (IVM) media improved the bovine oocyte maturation and early embryo development. The addition of BOEC–Exo not only significantly enhanced the polar body exclusion, but also enhanced the expression of connexins in cumulus oocyte complexes (COCs). Likewise, the reactive oxygen species (ROS) level, protein expressions of SIRT-1, and mitochondrial membrane potential (ΔΨm) also suggested that BOEC–Exo addition to IVM media is highly beneficial for in vitro bovine oocyte maturation. Furthermore, BOEC–Exo treatment to the primary cultured bovine cumulus cells significantly attenuated apoptosis, which also showed its positive influence on the COCs. Moreover, oocytes that were matured in the presence of BOEC–Exo led to the production of a significantly higher quantity and quality of day-8 blastocysts. Additionally, the BOEC–Exo treated blastocysts had a higher implantation potential when compared with the control. Our results suggest that the addition of BOEC–Exo to IVM media significantly enhanced the percentage of oocytes maturation and improved the embryo quantity and quality.

Abstract

Exosomes are nano-sized vesicles with abundant nucleic acids, proteins, lipids, and other regulatory molecules. The aim of this study was to examine the effect of BOEC–Exo on bovine in vitro oocyte maturation and in vitro embryo development. We found that a 3% Exo supplementation to IVM media significantly enhanced the oocyte maturation and reduced the accumulation of ROS in MII-stage bovine oocytes. Oocyte maturation related genes (GDF9 and CPEB1) also confirmed that 3% Exo treatment to oocytes significantly (p < 0.05) enhanced the oocyte maturation. Next, we cultured bovine cumulus cells and assessed the effects of 3% Exo, which showed a reduced level of apoptotic proteins (caspase-3 and p-NF-κB protein expressions). Furthermore, we examined the gap junction (CX43 and CX37) and cumulus cells expansion related genes (HAS2, PTX3, and GREM1) in cumulus–oocyte complexes (COCs), and all those genes showed significantly (p < 0.05) higher expressions in 3% Exo-treated COCs as compared with the control group. Moreover, peroxisome proliferator-activated receptors (PPARs) and lipid metabolism-related genes (CPT1 and FABP3) were also analyzed in both the control and 3% Exo groups and the results showed significant (p < 0.05) enhancement in the lipid metabolism. Finally, the oocytes matured in the presence of 3% Exo showed a significantly higher rate of embryo development and better implantation potential. Finally, we concluded that Exo positively influenced bovine oocyte in vitro maturation and improved the early embryo’s developmental competence.

Effects of Donor Cell Types on the Development of Bovine Embryos Using Cytoplasm Injection Cloning Technology

Cytoplasm injection cloning technology (CICT) is an efficient technique for evaluating the developmental potential of cloned embryos. In this study, we investigated the effects of donor cell type on the developmental potential and quality of cloned bovine embryos. Adult fibroblasts (AFs) and embryonic cells (ECs) were used as donor cells to clone bovine embryos using CICT. We initially used AF cells to develop cloned embryos and then cultured the cloned day-8 blastocysts for 10 days to obtain ECs as donor cells for second embryo cloning. We found that the bovine blastocysts cloned using AF cells had significantly reduced developmental rates, embryo quality, and ratios of inner cell mass (ICM) to the total number of cells compared to those using ECs as donor cells. Furthermore, there were significant differences in the DNA methyltransferase-, histone deacetylation-, apoptosis-, and development-related genes at the blastocyst stage in embryos cloned from AFs compared to those in embryos cloned from ECs. Our results suggest that using ECs as donor cells for nuclear transfer enhances the quantity and quality of cloned embryos. However, further investigation is required in terms of determining pregnancy rates and developing cloned embryos from different donor cell types.

Constitutive Expression of TERT Enhances β-Klotho Expression and Improves Age-Related Deterioration in Early Bovine Embryos

Age-associated decline in oocyte quality is one of the dominant factors of low fertility. Aging alters several key processes, such as telomere lengthening, cell senescence, and cellular longevity of granulosa cells surrounding oocyte. To investigate the age-dependent molecular changes, we examined the expression, localization, and correlation of telomerase reverse transcriptase (TERT) and β-Klotho (KLB) in bovine granulosa cells, oocytes, and early embryos during the aging process. Herein, cumulus-oocyte complexes (COCs) obtained from aged cows (>120 months) via ovum pick-up (OPU) showed reduced expression of β-Klotho and its co-receptor fibroblast growth factor receptor 1 (FGFR1). TERT plasmid injection into pronuclear zygotes not only markedly enhanced day-8 blastocysts’ development competence (39.1 ± 0.8%) compared to the control (31.1 ± 0.5%) and D-galactose (17.9 ± 1.0%) treatment groups but also enhanced KLB and FGFR1 expression. In addition, plasmid-injected zygotes displayed a considerable enhancement in blastocyst quality and implantation potential. Cycloastragenol (CAG), an extract of saponins, stimulates telomerase enzymes and enhances KLB expression and alleviates age-related deterioration in cultured primary bovine granulosa cells. In conclusion, telomerase activation or constitutive expression will increase KLB expression and activate the FGFR1/β-Klotho pathway in bovine granulosa cells and early embryos, inhibiting age-related malfunctioning.

Dexmedetomidine protects cardiac microvascular endothelial cells from the damage of ogd/r through regulation of the pparδ-mediated autophagy

BACKGROUND

Dexmedetomidine (Dex) exerts an effective therapeutic role in numerous diseases associated with ischemia/reperfusion (I/R) injury via its anti-apoptosis properties. Therefore, this study explores the cardioprotective effects of Dex in cardiac microvascular endothelial cells (CMECs) in response to oxygen-glucose deprivation and re-oxygenation (OGD/R) injury and its potential mechanism.

MATERIAL AND METHODS

CMECs were pretreatment with different concentration of Dex, then exposed to OGD/R. Cell viability was measured with CCK-8 assay. Apoptosis was evaluated by flow cytometry, and apoptosis-related protein was determined by Western blot. Autophagy was assessed by transmission electron microscopy and autophagy-related proteins. Besides, the role peroxisome proliferator-activated receptors (PPARδ) in Dex-mediated anti-apoptosis property was validated with agonist and antagonist.

RESULTS

OGD/R significantly decreased cell viability, increased reactive oxygen species, caused disorder of autophagy, and increased apoptosis in CMECs. Dex enhanced the viability of the OGD/R-treated CMECs and effectively decreased reactive oxygen species production. Autophagy in CMECs was activated by Dex, as evidenced by the increase in the ratio of LC3B-II/I, expression level of Beclin1 and number of autophagosomes in the OGD/R-induced CMECs. The mechanistic investigation indicated that PPARδ antagonist GW501516 aggravated cell damage following OGD/R, while PPARδ agonist GW6471 partly abolished the Dex-mediated protective effects.

CONCLUSIONS

Dex activated the PPARδ-AMPK-PGC-1α pathway-mediated autophagy in CMECs, therefore to inhibit excessive apoptosis induced by OGD/R. Dex may potentially be a therapeutic intervention for myocardial I/R injury.

SHP2 Nuclear/Cytoplasmic Trafficking in Granulosa Cells Is Essential for Oocyte Meiotic Resumption and Maturation

Src-homology-2-containing phosphotyrosine phosphatase (SHP2), a classic cytoplasmic protein and a major regulator of receptor tyrosine kinases and G protein-coupled receptors, plays a significant role in preimplantation embryo development. In this study, we deciphered the role of SHP2 in the somatic compartment of oocytes during meiotic maturation. SHP2 showed nuclear/cytoplasmic localization in bovine cumulus and human granulosa (COV434) cells. Follicle-stimulating hormone (FSH) treatment significantly enhanced cytoplasmic SHP2 localization, in contrast to the E₂ treatment, which augmented nuclear localization. Enhanced cytoplasmic SHP2 was found to negatively regulate the expression of the ERα-transcribed NPPC and NPR2 mRNAs, which are vital for oocyte meiotic arrest. The co-immunoprecipitation results revealed the presence of the SHP2/ERα complex in the germinal vesicle-stage cumulus-oocyte complexes, and this complex significantly decreased with the progression of meiotic maturation. The complex formation between ERα and SHP2 was also confirmed by using a series of computational modeling methods. To verify the correlation between SHP2 and NPPC/NPR2, SHP2 was knocked down via RNA interference, and NPPC and NPR2 mRNAs were analyzed in the control, E₂, and FSH-stimulated COV434 cells. Furthermore, phenyl hydrazonopyrazolone sulfonate 1, a site-directed inhibitor of active SHP2, showed no significant effect on the ERα-transcribed NPPC and NPR2 mRNAs. Taken together, these findings support a novel nuclear/cytoplasmic role of SHP2 in oocyte meiotic resumption and maturation.

Advances in fatty acids nutrition in dairy cows: from gut to cells and effects on performance

High producing dairy cows generally receive in the diet up to 5-6% of fat. This is a relatively low amount of fat in the diet compared to diets in monogastrics; however, dietary fat is important for dairy cows as demonstrated by the benefits of supplementing cows with various fatty acids (FA). Several FA are highly bioactive, especially by affecting the transcriptome; thus, they have nutrigenomic effects. In the present review, we provide an up-to-date understanding of the utilization of FA by dairy cows including the main processes affecting FA in the rumen, molecular aspects of the absorption of FA by the gut, synthesis, secretion, and utilization of chylomicrons; uptake and metabolism of FA by peripheral tissues, with a main emphasis on the liver, and main transcription factors regulated by FA. Most of the advances in FA utilization by rumen microorganisms and intestinal absorption of FA in dairy cows were made before the end of the last century with little information generated afterwards. However, large advances on the molecular aspects of intestinal absorption and cellular uptake of FA were made on monogastric species in the last 20 years. We provide a model of FA utilization in dairy cows by using information generated in monogastrics and enriching it with data produced in dairy cows. We also reviewed the latest studies on the effects of dietary FA on milk yield, milk fatty acid composition, reproduction, and health in dairy cows. The reviewed data revealed a complex picture with the FA being active in each step of the way, starting from influencing rumen microbiota, regulating intestinal absorption, and affecting cellular uptake and utilization by peripheral tissues, making prediction on in vivo nutrigenomic effects of FA challenging.

Growth Factors, and Cytokines; Understanding the Role of Tyrosine Phosphatase SHP2 in Gametogenesis and Early Embryo Development

Growth factors and cytokines have vital roles in germ cell development, gamete maturation, and early embryo development. Cell surface receptors are present for growth factors and cytokines to integrate with and trigger protein signaling in the germ and embryo intracellular milieu. Src-homology-2-containing phosphotyrosine phosphatase (SHP2) is a ubiquitously expressed, multifunctional protein that plays a central role in the signaling pathways involved in growth factor receptors, cytokine receptors, integrins, and G protein-coupled receptors. Over recent decades, researchers have recapitulated the protein signaling networks that influence gamete progenitor specification as well as gamete differentiation and maturation. SHP2 plays an indispensable role in cellular growth, survival, proliferation, differentiation, and migration, as well as the basic events in gametogenesis and early embryo development. SHP2, a classic cytosolic protein and a key regulator of signal transduction, displays unconventional nuclear expression in the genital organs. Several observations provided shreds of evidence that this behavior is essential for fertility. The growth factor and cytokine-dependent roles of SHP2 and its nuclear/cytoplasmic presence during gamete maturation, early embryonic development and embryo implantation are fascinating and complex subjects. This review is intended to summarize the previous and recent knowledge about the SHP2 functions in gametogenesis and early embryo development.