Predominant expression of the beta subunit of prolyl 4-hydroxylase (disulfide isomerase) in human extravillous trophoblasts

Screening Candidate Genes Regulating Placental Development from Trophoblast Transcriptome at Early Pregnancy in Dazu Black Goats (Capra hircus)

Simple Summary

The trophoblast is an original placental tissue whose normal proliferation, differentiation, migration, adhesion, and angiopoiesis are essential for placenta formation and fetal survival during early pregnancy. However, the key genes and molecular mechanisms involved in placenta development in goats are unknown. Herein, the morphology and histological structures of trophoblast tissues from day 20 to 30 of pregnancy were determined. RNA-sequencing was used to screen potential functional genes in common highly expressed and differentially expressed genes. RAP1 signaling pathway was used as the contact center and coordinated with other pathways to regulate placenta development. This study could provide insights into the molecular mechanisms underlying ruminant placentation.

Abstract

This study explored the trophoblast transcriptome to understand potential functional genes involved in early placental development in goats and their enriched signaling pathways. Trophoblast samples were collected from nine Dazu Black goats on days 20, 25, and 30 of pregnancy (D20, D25, and D30). As the pregnancy progressed, the morphology and histological structures showed significant growth, adhesion, and angiogenesis. A total of 23,253 commonly expressed genes (CEGs) and 4439 differently expressed genes (DEGs) were detected by RNA sequencing. The common highly expressed genes (ChEGs) (the top 100 CEGs) with the highest FPKM percentage (29.9%) of all CEGs were annotated to the ribosome pathway and maintain pregnancy. DEGs were abundant in D30 vs. D20 (3715 DEGs). Besides, the DEGs were associated with the inhibition of oxidative phosphorylation and activation of PI3K-Akt, focal adhesion, ECM–receptor interaction, Rap1, and CAM signaling pathways. The RAP1 may be a central pathway since it coordinates with others to regulate the cell proliferation, invasion, migration, and fusion of trophoblasts. qRT-PCR and Western blot analysis confirmed the transcriptional expression in IGF1, VEGFC, RAPGEF3, PIK3CA, AKT3, ITGB3, ITGA11, SPP1, NOS1, and ATP6V0B genes and protein levels in VEGF, RAPGEF3, and Akt. This is the first study of transcriptome profiling in goat placenta and provides diverse genetic resources for further research on placenta development.

Interstitial Cells in the Musculature of the Gastrointestinal Tract: Cajal and Beyond

Expression of the receptor tyrosine kinase KIT on cells referred to as interstitial cells of Cajal (ICC) has been instrumental during the past decade in the tremendous interest in cells in the interstitium of the smooth muscle layers of the digestive tract. ICC generate the pacemaker component (electrical slow waves of depolarization) of the smooth musculature and are involved in neurotransmission. By integration of ICC functions, substantial progress has been made in our understanding of the neuromuscular control of gastrointestinal motility, opening novel therapeutic perspectives. In this article, the ultrastructure and light microscopic morphology, as well as the functions and the development of ICC and of neighboring fibroblast-like cells (FLC), are critically reviewed. Directions for future research are considered and a unifying concept of mesenchymal cells, either KIT positive (the "ICC") or KIT negative "non-Cajal" (including the FLC and possibly also other cell types) cell types in the interstitium of the smooth musculature of the gastrointestinal tract, is proposed. Furthermore, evidence is accumulating to suggest that, as postulated by Santiago Ramon y Cajal, the concept of interstitial cells is not likely to be restricted to the gastrointestinal musculature.

Ultrastructural localisation and further biochemical characterisation of prolyl 4-hydroxylase from Phaseolus vulgaris: comparative analysis

Prolyl 4-hydroxylase (EC 1.14.11.2), the enzyme responsible for the post-translational hydroxylation of peptide proline, has been well described in animals but has been little studied in plants. The best characterised example is the enzyme from French bean (Phaseolus vulgaris). In this study, the biochemical properties of this plant enzyme were examined in more detail and, using specific polyclonal antibodies, the localisation of the enzyme was determined. Both alpha- and beta-subunits did not show multiple forms, suggesting a relatively broad specificity of the enzyme complex with respect to the target hydroxylated amino acid sequences. Antibodies to the mammalian and Chlamydomonas enzymes cross-react with the higher plant subunits, indicating that some epitopes are highly conserved. The P. vulgaris enzyme was inhibited by analogues of oxoglutarate, but was not susceptible to doxorubicin. Inhibition of the bean enzyme by an oxaloglycine derivative resulted in the retention of the target (hydroxy)proline-rich protein in the endomembrane system. Immunolocalisation of the enzyme showed close association with the endoplasmic reticulum and Golgi apparatus in root tip cells of P. vulgaris or Tropaeolum majus. This localisation was particularly pronounced in Golgi-associated vesicles of young root tip cells of T. majus, cell types where rapid synthesis and deposition of wall material was observed. These data are consistent with the hypothesis, proposed by Bolwell [G.P. Bolwell, Dynamic aspects of the plant extracellular matrix, Int. Rev. Cytol. 146 (1993) 261-324], that protein hydroxylation must be completed before the glycosylation of the target (hydroxy)proline-rich glycoproteins in the Golgi stack.

Epithelioid trophoblastic tumor: a neoplasm distinct from choriocarcinoma and placental site trophoblastic tumor simulating carcinoma

This report describes the clinicopathologic and immunohistochemical features of 14 cases of epithelioid trophoblastic tumor (ETT), a distinctive but rare gestational trophoblastic tumor. The patients with this neoplasm were in the reproductive age group and presented with abnormal vaginal bleeding. Although diagnosis was usually associated with a gestational event, the latter was sometimes remote. Two of the 14 patients presented with extrauterine ETT without evidence of prior gestational trophoblastic disease in the uterus. Serum human chorionic gonadotropin levels were elevated in eight of nine patients in whom this information was available. In the uterus, ETT presented as a discrete, hemorrhagic, solid and cystic lesion that was located either in the fundus, lower uterine segment, or endocervix. Microscopically, the tumor was composed of a relatively uniform population of mononucleate intermediate trophoblastic cells forming nests and solid masses. The cells resemble the trophoblastic cells in the chorion laeve, and we have therefore designated them "chorionic-type intermediate trophoblast." Typically, islands of trophoblastic cells were surrounded by extensive necrosis and were associated with a hyaline-like matrix creating a "geographic" pattern that is quite characteristic of this lesion. The mean mitotic count was two mitoses per 10 high-power fields, and the average Ki-67 nuclear labeling index was 18%. Immunohistochemically, all cases were diffusely positive for inhibin-alpha, cytokeratin (AE1/AE3), epithelial membrane antigen, E-cadherin, prolyl 4-hydroxylase, and epidermal growth factor receptor but were only focally immunoreactive for human placental lactogen, human chorionic gonadotropin, PlAP, and Mel-CAM. The monomorphic growth pattern of ETT resembles placental site trophoblastic tumor to a much greater degree than choriocarcinoma which is characterized by a dimorphic population of trophoblast. In contrast to placental site trophoblastic tumor, the cells of ETT are smaller and display less nuclear pleomorphism. In addition, ETT grows in a nodular fashion compared with the infiltrative pattern of placental site trophoblastic tumor. In some of the cases, the trophoblastic cells in ETT replaced the endocervical surface epithelium, giving the appearance that the tumor was derived from the cervix. Moreover, because the associated hyaline-like material in ETT resembles keratin, the tumor can be misinterpreted as a keratinizing squamous cell carcinoma of the cervix. Ten patients underwent total hysterectomy and two had an endometrial curettage only. The two patients who presented with extrauterine ETT underwent small bowel resection and lung resection. Two of 12 patients with ETT in the uterus developed metastasis in the lungs and bone. One of these patients is alive with disease at 43 months and one patient was lost to follow-up after 2 months. One of the two patients who had extrauterine disease died of widespread tumor 36 months after diagnosis. The remainder of the patients are alive and well from 1 to 120 months. In summary, ETT is a rare trophoblastic tumor that simulates carcinoma and can behave in a malignant fashion. It appears to be less aggressive than choriocarcinoma, more closely resembling the behavior of placental site trophoblastic tumor. Based on the morphologic and immunohistochemical features, it appears that ETT develops from neoplastic transformation of chorionic-type intermediate trophoblast.

Immunohistochemical localization of the beta subunit of prolyl 4-hydroxylase in human alveolar epithelial cells

The beta subunit of prolyl 4-hydroxylase, the protein-disulfide isomerase (PDJ), catalyzes the hydroxylation of proline residues of collagens and proteins with collagen-like structure, a step essential for the folding of the procollagen chains to form triple-helices. In the present study, we report the selective immunohistological localization of PDI in type II alveolar and bronchial epithelial cells. The detection of the hidden antigen with the monoclonal antibody 5B5 is usually not successful in paraffin sections but was possible after microwave pretreatment of tissue sections. In cases of severe lung injury (fibrosing alveolitis) enhanced immunoreactivity was found for this enzyme in epithelial, endothelial as well as interstitial cells and in alveolar macrophages. The results indicate a possible involvement of the pulmonary epithelial cells in the upregulation of collagen production during the process of fibrosis.