Effects of digital health interventions on the psychological outcomes of perinatal women: umbrella review of systematic reviews and meta-analyses

ABSTRACTEvidence about the effects of digital health interventions (DHIs) on the psychological outcomes of perinatal women is increasing but remains inconsistent. An umbrella review was conducted to (1) assess the effect of DHIs on depressive, anxiety and stress symptoms and (2) compare the effects of DHIs on different digital platforms and population natures. Ten databases were searched from inception until December 23, 2022. The Hartung-Knapp-Sidik-Jonkman random-effects meta-analyses were utilised. Methodological quality was evaluated using the Assessment of Multiple Systematic Reviews 2 (AMSTAR-2). Twenty-four systematic reviews with 41 meta-analyses involving 45,509 perinatal women from 264 primary studies were included. The credibility of the evidence of meta-analyses was rated as highly suggestive (4.88%), suggestive (26.83%), weak (51.22%) or non-significant (17.07%) according to AMSTAR-2. Our findings suggest that DHIs are beneficial for reducing stress symptoms. However, conflicting effects were found on anxiety symptoms. Subgroup and meta-regression analyses suggested that DHIs effectively improve depressive symptoms in postnatal women, and DHIs using the website platform are highly effective in stress reduction. DHIs can be implemented adjuvant to usual obstetric care to improve depressive and stress symptoms. Additional well-designed RCTs with long-term follow-up are warranted.

Fucosylation of Cripto is required for its ability to facilitate nodal signaling

O-linked fucose modification is rare and has been shown to occur almost exclusively within epidermal growth factor (EGF)-like modules. We have found that the EGF-CFC family member human Cripto-1 (CR) is modified with fucose and through a combination of peptide mapping, mass spectrometry, and sequence analysis localized the site of attachment to Thr-88. The identification of a fucose modification on human CR within its EGF-like domain and the presence of a consensus fucosylation site within all EGF-CFC family members suggest that this is a biologically important modification in CR, which functionally distinguishes it from the EGF ligands that bind the type 1 erbB growth factor receptors. A single CR point mutation, Thr-88 --> Ala, results in a form of the protein that is not fucosylated and has substantially weaker activity in cell-based CR/Nodal signaling assays, indicating that fucosylation is functionally important for CR to facilitate Nodal signaling.

Activin/nodal responsiveness and asymmetric expression of a Xenopus nodal-related gene converge on a FAST-regulated module in intron 1

Vertebrate Nodal-related factors play central roles in mesendoderm induction and left-right axis specification, but the mechanisms regulating their expression are largely unknown. We identify an element in Xnr1 intron 1 that is activated by activin and Vg1, autoactivated by Xnrs, and suppressed by ventral inducers like BMP4. Intron 1 contains three FAST binding sites on which FAST/Smad transcriptional complexes can assemble; these sites are differentially involved in intron 1-mediated reporter gene expression. Interference with FAST function abolishes intron 1 activity, and transcriptional activation of Xnrs by activin in embryonic tissue explant assays, identifying FAST as an essential mediator of Xnr autoregulation and/or ‘signal relay’ from activin-like molecules. Furthermore, the mapping of endogenous activators of the Xnr1 intronic enhancer within Xenopus embryos agrees well with the pattern of Xnr1 transcription during embryogenesis. In transgenic mice, Xnr1 intron 1 mimics a similarly located enhancer in the mouse nodal gene, and directs FAST site-dependent expression in the primitive streak during gastrulation, and unilateral expression during early somitogenesis. The FAST cassette is similar in an ascidian nodal-related gene, suggesting an ancient origin for this regulatory module. Thus, an evolutionarily conserved intronic enhancer in Xnr1 is involved in both mesendoderm induction and asymmetric expression during left-right axis formation.

Left-right asymmetric expression of lefty2 and nodal is induced by a signaling pathway that includes the transcription factor FAST2

The left-right (L-R) asymmetric expression of lefty2 and nodal is controlled by a left side-specific enhancer (ASE). The transcription factor FAST2, which can mediate signaling by TGF beta and activin, has now been identified as a protein that binds to a conserved sequence in ASE. These FAST2 binding sites were both essential and sufficient for L-R asymmetric gene expression. The Fast2 gene is bilaterally expressed when nodal and lefty2 are expressed on the left side. TGF beta and activin can activate the ASE activity in a FAST2-dependent manner, while Nodal can do so in the presence of an EGF-CFC protein. These results suggest that the asymmetric expression of lefty2 and nodal is induced by a left side-specific TGF beta-related factor, which is most likely Nodal itself.

The role of FAST-1 and Smads in transcriptional regulation by activin during early Xenopus embryogenesis

Smads are signal transducers for the transforming growth factor-beta superfamily of factors. In early Xenopus embryos, the transforming growth factor-beta member activin induces the gene Mix.2 by stimulating the formation of a multiprotein complex, activin-responsive factor (ARF). This complex contains Smad2 or Smad3, Smad4, and a novel forkhead transcription factor, FAST-1, and binds to an enhancer (activin-responsive element; ARE) that confers activin regulation of Mix.2 transcription. Both FAST-1 and Smads can bind directly to the ARE; we have investigated 1) the role of FAST-1 and Smad DNA binding sites in ARF recognition of the ARE, 2) the contributions of FAST-1 and Smad binding to ARF binding in vitro and to ARE regulation in early Xenopus embryos, 3) the extent to which different Smads can replace Smad4 in regulation of the ARE. We find that ARF binds to ARE through both FAST-1 and Smad binding sites. FAST-1 recognition of the ARE is essential both for ARF binding in vitro and activin regulation in vivo. In contrast, Smad binding of ARE is unnecessary for ARF binding or activin regulation but does enhance the binding and regulatory activity of ARF. Also, Smad3 can partially substitute for Smad4 in the regulation of the ARE. These observations elucidate how broadly expressed signal transducers (Smads) regulate a developmentally specific transcriptional response in conjunction with a temporally restricted transcription factor, FAST-1.

Expression of Radical fringe in limb-bud ectoderm regulates apical ectodermal ridge formation

The apical ectodermal ridge of the vertebrate limb bud lies at the junction of the dorsal and ventral ectoderm and directs patterning of the growing limb. Its formation is directed by the boundary between cells that do and cells that do not express the gene Radical fringe. This is similar to the establishment of the margin cells at the Drosophila wing dorsoventral border by fringe. Radical fringe expression in chick-limb dorsal ectoderm is established in part through repression by Engrailed-1 in the ventral ectoderm.