Phospholipase C inhibits apoptosis of porcine oocytes cultured in vitro

RNA binding proteins are potential novel biomarkers of egg quality in yellow catfish

BACKGROUND

Egg quality is a major concern in fish reproduction and development. An effective evaluation of egg quality prior to fertilization is helpful in improving the fertilization rate and survival rate of the larva. In this study, we aim to identify quality instructors from the combination study of fertilization rate, hatching rate, embryo malformation rate and gene expression profile.

RESULTS

Eggs from 25 female fish were fertilized with sperm from the same fish. The egg quality was determined by the fertilization rates, hatching rate and embryo malformation rate and divided into three categories, low-quality (< 35%), medium-quality (35 to 75%), and high-quality (> 75%). Due to the distinct difference in fertilization, hatching and embryo malformation rate between low-quality eggs and high-quality eggs, these two groups were considered for the identification of quality markers. Then RNA-seq was performed for the originally preserved eggs from the low-quality group and high-quality group. We profiled the differentially expressed genes and identified a group of RNA-binding proteins (RBPs) as potential regulators. Gene function analysis indicated that most of these genes were enriched in RNA-regulated pathways including RNA processing. The RBPs were more related to egg quality from the PLS-DA analysis. Finally, gene expression was validated by qRT-PCR.

CONCLUSIONS

We found a cluster of RBP genes including igf2bp3, zar1, elavl1, rbm25b and related regulatory factors including yy1, sirt1, anp32e, btg4 as novel biomarkers of egg quality.

17β-estradiol improves the developmental ability, inhibits reactive oxygen species levels and apoptosis of porcine oocytes by regulating autophagy events

OBJECTIVES

Estrogen plays a critical role in the development and apoptosis of oocytes. Autophagy is an evolutionarily conserved and exquisitely regulated self-eating cellular process with important biological functions including the regulation of reproduction. This study aimed to determine the effect of autophagy regulated by the biologically active form of estrogen (17β-estradiol) in porcine oocyte maturation in vitro.

MATERIALS AND METHODS

We measured the effects of oocyte developmental competencies and autophagic activity in the porcine oocyte regulated by 17β-estradiol using autophagic inhibitor (Autophinib). In addition, we studied the role of autophagy in reactive oxygen species (ROS) levels, mitochondrial distribution, Ca²⁺ production, mitochondrial membrane potential (ΔΨm), and early apoptosis by caspase-3, -8 activity in the mature oocytes.

RESULTS

The results showed that the oocyte meiotic progression and early embryonic development were gradually decreased with Autophinib treatment, which was improved by 17β-estradiol. Immunofluorescence experiments revealed that 17β-estradiol primarily could promote the autophagy in the mature oocytes, and block the reduced-autophagic events by Autophinib. Moreover, 17β-estradiol improved the Autophinib induced high ROS levels, abnormal mitochondrial distribution and low Ca²⁺ production in mature oocytes. Analyses of early apoptosis and ΔΨm showed that autophagy inhibition was accompanied by increased cellular apoptosis, and 17β-estradiol reduced apoptosis rates of mature oocytes. Importantly, autophagy was downregulated by treatment with Autophinib, an activation of caspase-8 and cleaved caspase-3 increased. Those effects were abolished by 17β-estradiol, which could upregulate autophagy.

CONCLUSIONS

Our study have showed important implications that 17β-estradiol could promote efficacy of the development of porcine oocytes, enhance the autophagy, reduce ROS levels and apoptosis activity in vitro maturation.

TRPM7 Upregulate the Activity of SMAD1 through PLC Signaling Way to Promote Osteogenesis of hBMSCs

TRPM7 is a member of the transient receptor potential cation channel (TRP channel) subfamily M and possesses both an ion channel domain and a functional serine/threonine α-kinase domain. It has been proven to play an essential role in the osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs). However, the signaling pathway and molecular mechanism for TRPM7 in regulating osteogenic differentiation remain largely unknown. In this study, the potential role and mechanism of TRPM7 in the osteogenic differentiation of hBMSCs were investigated. The results showed that the expression of TRPM7 mRNA and protein increased, as did the osteogenic induction time. Upregulation or inhibition of TRPM7 could promote or inhibit the osteogenic differentiation of hBMSCs for 14 days. It was also found that the upregulation or inhibition of TRPM7 promoted or inhibited the activity of PLC and SMAD1, respectively, during osteogenic differentiation. PLC could promote osteogenic differentiation by upregulating the activity of SMAD1. However, inhibition of PLC alone could reduce the activity of SMAD1 but not inhibit completely the activation of SMAD1. Therefore, we inferred that it is an important signaling pathway for TRPM7 to upregulate the activity of SMAD1 through PLC and thereby promote the osteogenic differentiation of hBMSCs, but it is not a singular pathway. TRPM7 may also regulate the activation of SMAD1 through other ways, except for PLC, during osteogenic differentiation of hBMSCs.