Search

Little is known about how the fibrotic gut stiffening caused by inflammatory bowel diseases (IBD) directs the fate of intestinal stem cells (ISCs). To address this question we first developed a novel long-term culture of quasi-3D gut organoids plated on hydrogel matrix of varying stiffness. Stiffening from 0.6kPa to 9.6kPa significantly reduces Lgr5high ISCs and Ki67+ progenitor cells while promoting their differentiation towards goblet cells. These stiffness-driven events are attributable to YAP nuclear translocation. Matrix stiffening also extends the expression of the stemness marker Olfactomedin 4 (Olfm4) into villus-like regions, mediated by cytoplasmic YAP. We next used single-cell RNA sequencing to generate for the first time the stiffness-regulated transcriptional signatures of ISCs and their differentiated counterparts. These signatures confirm the impact of stiffening on ISC fate and additionally suggest a stiffening-induced switch in metabolic phenotype, from oxidative phosphorylation to glycolysis. Finally, we used colon samples from IBD patients as well as chronic colitis murine models to confirm the in vivo stiffening-induced epithelial deterioration similar to that observed in vitro. Together, these results demonstrate stiffness-dependent ISC reprograming wherein YAP nuclear translocation diminishes ISCs and Ki67+ progenitors and drives their differentiation towards goblet cells, suggesting stiffening as potential target to mitigate gut epithelial deterioration during IBD.

Children who have experienced early relational trauma in the realms of neglect and abuse may go on to develop a range of dissociative states of being as a consequence or as a defence. Child psychotherapists are frequently referred children struggling with such a legacy, yet for historical reasons dissociation is notably absent from the psychoanalytic literature and not a formal part of our professional training. This thesis aims to illuminate how dissociative children may present in psychotherapy sessions and to assess whether there are indications that traditional psychoanalytic child psychotherapy technique may need adjusting if treatment is to be most effective. Current theory regarding the aetiology of dissociative pathology is presented including the significant contributions from attachment and neuroscience research, and the slender view offered by psychoanalytic theory is elucidated. Case histories of two of the three participant children are presented with specific reference to attachment and trauma. Process recording notes from the psychotherapy of all three dissociative children are subjected to thematic analysis to arrive at two sets of patient and therapist related themes which are then recursively discussed in fine detail to determine what evidence the material provides. The conclusion is drawn that whilst dissociative children present with some distinct difficulties, these do not dominate the therapeutic endeavour and are largely similar to the presentation of traumatised and attachment disordered patients with whom child psychotherapists are very familiar. Furthermore it is suggested that whilst child psychotherapists treating dissociative children should consider psychoeducuative, organising and validating interventions, their core psychoanalytic skills of withstanding and analysing hostile and perverse transference material, together with their experience in creatively bringing all parts of the self to the child‟s conscious awareness are central to helping dissociative children recover.