The requirement for protein kinase C delta (PRKCD) during preimplantation bovine embryo development

Abstract

Protein kinase C (PKC) delta (PRKCD) is a member of the novel PKC subfamily that regulates gene expression in bovine trophoblast cells. Additional functions for PRKCD in early embryonic development in cattle have not been fully explored. The objectives of this study were to describe the expression profile of PRKCD mRNA in bovine embryos and to examine its biological roles during bovine embryo development. Both PRKCD mRNA and protein are present throughout early embryo development and increases in mRNA abundance are evident at morula and blastocyst stages. Phosphorylation patterns are consistent with detection of enzymatically active PRKCD in bovine embryos. Exposure to a pharmacological inhibitor (rottlerin) during early embryonic development prevented development beyond the eight- to 16-cell stage. Treatment at or after the 16-cell stage reduced blastocyst development rates, total blastomere numbers and inner cell mass-to-trophoblast cell ratio. Exposure to the inhibitor also decreased basal interferon tau (IFNT) transcript abundance and abolished fibroblast growth factor-2 induction of IFNT expression. Furthermore, trophoblast adhesion and proliferation was compromised in hatched blastocysts. These observations provide novel insights into PRKCD mRNA expression profiles in bovine embryos and provide evidence for PRKCD-dependent regulation of embryonic development, gene expression and post-hatching events.

Interleukin-6 increases inner cell mass numbers in bovine embryos

“…To enable ICM and TE cell counting, we utilized an immunofluorescence protocol to mark the CDX2-positive TE cells. This is a TE specific marker in bovine blastocysts [35–40]. Binding specificity of the antibody used herein has been verified recently by the absence of staining in CDX2 knock-down bovine blastocysts [41].…”

“…At day 8 post-fertilization, ICM and TE cell numbers were determined in a subset of blastocysts [35]. All blastocysts were utilized when blastocysts numbers were low (< 10/treatment group/replicate).…”

Dysregulated epidermal growth factor and tumor growth factor-beta receptor signaling through GFAP-ACTA2 protein interaction in liver fibrosis

“…Various members of this PKC family have been implicated in progression of cell cycle, apoptosis and differentiation. 21 Protein kinase A family of proteins is activated in response to G coupled protein receptors 22 while PRKCD plays a key role in autophagy suppression which is achieved by the process of phosphorylation of AKT which further activates mTOR, specific for fibrolamellar carcinoma. 23 In current study, activity of c-SRC decreases with progressive liver fibrogenesis and hepatic stellate cell (HSC) activation.…”

Lack of protein kinase C‐delta (PKCδ) disrupts fertilization and embryonic development

“…Additional studies are needed to assess the mechanisms whereby the absence of PKCδ influences fetal and/or placental development at post‐implantation stages. While Prkcd −/− embryos developed to the blastocyst stage following in vitro fertilization with Prkcd‐ null sperm, further assessment of blastocyst quality is warranted since PKCδ can influence cavitation and blastocyst development (Eckert et al, ; Yang et al, ). It is also important to consider that embryo loss might be related to the increased autoimmunity in Prkcd‐ null mice, which are characterized by expansion of the B‐lymphocyte population as well as circulating autoreactive antibodies and infiltration of lymphocytes in many organs (Miyamoto et al, ).…”

“…Further studies demonstrate that PKCδ also associates with the second meiotic spindle, and is expressed in activated eggs (Tatone et al, ; Baluch et al, ). PKC activity was also shown to increase during fertilization (Tatone et al, ; Gonzalez‐Garcia et al, ), and various studies propose that PKCδ plays a role during egg activation as well as pre‐implantation embryo development (Pauken and Capco, ; Dehghani et al, ; Yang et al, ).…”