Adult attachment and prolonged grief:A systematic review and meta-analysis

Diagnoses characterized by severe, persistent and disabling grief have recently been added to the ICD-11 and DSM-5-TR as prolonged grief disorder. Adult attachment is widely assumed critical in the development, persistence, and treatment of prolonged grief, yet a meta-analysis on this topic is lacking. We conducted a systematic review (PROSPERO: CRD42021220511) searching PsycInfo, Web of Science, and PubMed (final search: August 2022) to identify and summarize quantitative research examining relationships between adult attachment (i.e., attachment anxiety, attachment avoidance, secure attachment, disorganized attachment) and prolonged grief symptoms. Thirty-one studies including 8347 bereaved adults were included. Attachment anxiety (r = 0.28, 95 % CI:0.23–0.32, k = 15) and attachment avoidance (r = 0.15, 95 % CI:0.05–0.26, k = 15) related positively to prolonged grief symptoms concurrently. We found no evidence of publication bias but did detect heterogeneity in effect sizes. Ten longitudinal analyses showed no evidence that insecure attachment styles increase prolonged grief symptoms. Attachment anxiety predicted better therapy outcomes. Insecure attachment styles are concurrently positively related to prolonged grief symptoms but do not increase grief severity. The role of adult attachment in contemporary grief theories may need reconsideration. Intensive longitudinal research should aim to clarify how dynamic changes in attachment to the deceased and others relate to changes in prolonged grief symptoms.</p

Dedifferentiation of Foetal CNS Stem Cells to Mesendoderm-Like Cells through an EMT Process

Tissue-specific stem cells are considered to have a limited differentiation potential. Recently, this notion was challenged by reports that showed a broader differentiation potential of neural stem cells, in vitro and in vivo, although the molecular mechanisms that regulate plasticity of neural stem cells are unknown. Here, we report that neural stem cells derived from mouse embryonic cortex respond to Lif and serum in vitro and undergo epithelial to mesenchymal transition (EMT)-mediated dedifferentiation process within 48 h, together with transient upregulation of pluripotency markers and, more notably, upregulation of mesendoderm genes, Brachyury (T) and Sox17. These induced putative mesendoderm cells were injected into early gastrulating chick embryos, which revealed that they integrated more efficiently into mesoderm and endoderm lineages compared to non-induced cells. We also found that TGFβ and Jak/Stat pathways are necessary but not sufficient for the induction of mesendodermal phenotype in neural stem cells. These results provide insights into the regulation of plasticity of neural stem cells through EMT. Dissecting the regulatory pathways involved in these processes may help to gain control over cell fate decisions

Genomic Targets of Brachyury (T) in Differentiating Mouse Embryonic Stem Cells

The T-box transcription factor Brachyury (T) is essential for formation of the posterior mesoderm and the notochord in vertebrate embryos. Work in the frog and the zebrafish has identified some direct genomic targets of Brachyury, but little is known about Brachyury targets in the mouse.Here we use chromatin immunoprecipitation and mouse promoter microarrays to identify targets of Brachyury in embryoid bodies formed from differentiating mouse ES cells. The targets we identify are enriched for sequence-specific DNA binding proteins and include components of signal transduction pathways that direct cell fate in the primitive streak and tailbud of the early embryo. Expression of some of these targets, such as Axin2, Fgf8 and Wnt3a, is down regulated in Brachyury mutant embryos and we demonstrate that they are also Brachyury targets in the human. Surprisingly, we do not observe enrichment of the canonical T-domain DNA binding sequence 5'-TCACACCT-3' in the vicinity of most Brachyury target genes. Rather, we have identified an (AC)(n) repeat sequence, which is conserved in the rat but not in human, zebrafish or Xenopus. We do not understand the significance of this sequence, but speculate that it enhances transcription factor binding in the regulatory regions of Brachyury target genes in rodents.Our work identifies the genomic targets of a key regulator of mesoderm formation in the early mouse embryo, thereby providing insights into the Brachyury-driven genetic regulatory network and allowing us to compare the function of Brachyury in different species