Biology subjects

Forde, N.

Publications and source records attributed to Forde, N..

20 records · Page 2Linked to original sources

bioRxiv2020

The role of CAPG in molecular communication between the embryo and the uterine endometrium: Is its function conserved in species with different implantation strategies?

During the pre-implantation period of pregnancy in eutherian mammals, changes to the uterine endometrium are required (both at the transcriptional and protein level) to facilitate the endometrium becoming receptive to an implanting embryo. We know that the developing conceptus (embryo and extraembryonic membranes) produces proteins during this developmental stage. We hypothesised that this common process in early pregnancy in eutheria may be facilitated by highly conserved conceptus-derived proteins such as macrophage capping protein CAPG. More specifically, we propose that CAPG may share functionality in modifying the transcriptome of the endometrial epithelial cells to facilitate receptivity to implantation in species with different implantation strategies, such as human and bovine. A recombinant bovine form of CAPG (91% sequence identity between bovine and human) was produced and bovine endometrial epithelial (bEECs) and stromal (bESCs) cells and human endometrial epithelial cells (hEECs) were cultured for 24 h with or without rbCAPG. RNA sequencing and quantitative real-time PCR analysis was used to assess the transcriptional response to rbCAPG (Control, vehicle, CAPG 10, 100, 1000 ng/ml: n=3 biological replicates per treatment per species). Treatment of bEECs with CAPG resulted in changes to 1052 transcripts (629 increased and 423 decreased) compared to vehicle controls, including those previously only identified as regulated by interferon-tau, the pregnancy recognition signal in cattle. Treatment of hEECs with bovine CAPG increased expression of transcripts previously known to interact with CAPG in different systems (CAPZB, CAPZA2, ADD1 and ADK) compared with vehicle controls (P<0.05). In conclusion, we have demonstrated that CAPG, a highly conserved protein in eutherian mammals elicits a transcriptional response in the endometrial epithelium in two species with different implantation strategies that may facilitate uterine receptivity.

physiology↗

bioRxiv2018

Conformational flexibility of collagen molecules: composition and environmental effects

The predominant structural protein in vertebrates is collagen, which plays a key role in extracellular matrix and connective tissue mechanics. Despite its prevalence and physical importance in biology, the mechanical properties of molecular collagen are far from established. The flexibility of its triple helix is unresolved, with descriptions from different experimental techniques ranging from flexible to semirigid. Furthermore, it is unknown how collagen type (homo-vs. heterotrimeric) and source (tissue-derived vs. recombinant) influence flexibility. Using SmarTrace, a chain tracing algorithm we devised, we performed statistical analysis of collagen conformations collected with atomic force microscopy (AFM) to determine the proteins mechanical properties. Our results show that types I, II and III collagens - the key fibrillar varieties - exhibit molecular flexibilities that are very similar. However, collagen conformations are strongly modulated by salt, transitioning from compact to extended as KCl concentration increases, in both neutral and acidic pH. While analysis with a standard worm-like chain model suggests that the persistence length of collagen can attain almost any value within the literature range, closer inspection reveals that this modulation of collagens conformational behaviour is not due to changes in flexibility, but rather arises from the induction of curvature (either intrinsic or induced by interactions with the mica surface). By modifying standard polymer theory to include innate curvature, we show that collagen behaves as an equilibrated curved worm-like chain (cWLC) in two dimensions. Analysis within the cWLC model shows that collagens curvature depends strongly on pH and salt, while its persistence length does not. Thus, we find that triple-helical collagen is well described as semiflexible, irrespective of source, type, pH and salt environment. These results demonstrate that collagen is more flexible than its conventional description as a rigid rod, which may have implications for its cellular processing and secretion.

biophysics↗