Preeclampsia is a pregnancy complication classified by new onset of elevated blood pressure and proteinuria after 20 weeks of gestation. During preeclampsia, extra villous trophoblasts fail to adequately invade the myometrial spiral arteries, leading to incomplete and impaired vessel transformation and initiating or aggravating preeclampsia. Although NF-κB and proinflammatory cytokines have been reported to be related to trophoblast dysfunction, the underlying mechanism remains unclear. Herein, we demonstrated the miR-138/RELA axis modulating the migratory ability, and invasive ability of HTR-8/SVneo and JEG-3 cells, as well as the inflammatory factor levels in response to LPS stimulation. miR-138 expression was upregulated in preeclampsia placenta and LPS-stimulated HTR-8/SVneo and JEG-3 cell lines. miR-138 overexpression rescued the migratory and invasive ability of HTR-8/SVneo and JEG-3 cells inhibited by LPS stimulation, and decreased LPS-induced TNF-α and IL-6 levels. By binding the 3’-UTR of RELA, miR-138 negatively regulated p65 expression. The silencing of p65 also improved LPS-induced HTR-8/SVneo and JEG-3 cell dysfunction and TNF-α and IL-6 levels. More importantly, p65 overexpression partially reversed the functions of miR-138 overexpression upon both cells, indicating that miR-138 exerted its biological effects through targeting RELA. In conclusion, miR-138 improves LPS-induced inflammation and oxidative stress on trophoblasts through targeting RELA and affecting NF-κB signaling. The miR-138/RELA axis might be involved in preeclampsia pathogenesis, which requires further in vivo and clinical researches.

Background: Familial exudative vitreoretinopathy (FEVR) represents a clinically and genetically diverse ophthalmic disorder marked by incomplete development of retinal blood vessels. The NDP gene predominantly underlies X-linked FEVR. Methods: Copy number variation sequencing, chromosomal microarray, whole exome sequencing and Sanger sequencing were performed to identify and validate the candidate variant. The functional effect of the candidate variant was further investigated in HEK293 and HeLa cells with pcMINI and pcMINI-N vectors by means of minigene splicing assay in vitro. A summary of known pathogenic variants in the 5′-untranslated regions (5′ UTR) of the NDP gene and their clinical characteristics was formulated. Results: Whole exome sequencing identified a novel hemizygous 5′ UTR variant (NM_000266.4: c.-167_-166delinsAAGG) in the NDP gene. Sanger sequencing confirmed cosegregation of this variant with FEVR in the affected family members. Minigene splicing assays demonstrated that this variant resulted in partial deletions in exon 2. Pathogenic variations in the 5′ UTR were categorized into three types: 1. indels in dipyrimidine repeats (exon 1); 2. variants in splice sites (intron 1); and 3. variants in exon 2 (5′ UTR). Among patients with variations in dipyrimidine repeats (5 out of 8), most were diagnosed with retinopathy of prematurity (ROP). Patients with splice-site variants in intron 1 (4 out of 6) were predominantly diagnosed with Norrie disease (ND), while all patients (7 out of 7) with variations in exon 2 (5′ UTR region) were diagnosed with FEVR. Conclusions: A likely pathogenic variant was identified in 5′UTR of the NDP gene, and validation confirmed its impact on NDP splicing. The present analysis results also indicate a correlation between the location of the variations in 5′UTR and disease, providing assistance in disease prognosis.

Background: Osteogenesis imperfecta (OI) is a clinical and genetic disorder characterised by bone fragility, growth deficiency and skeletal deformity. Ninety per cent of OI cases are attributable to autosomal dominant variants in the COL1A1 and COL1A2 genes. Methods: Candidate variants were identified and verified through trio whole‐exome sequencing (trio‐WES), copy number variation sequencing (CNV‐seq) and Sanger sequencing. Minigene splicing assays were performed in HeLa and HEK293T cells with pcDNA3.1 and pcMINI‐C vectors to investigate the function of the candidate variants. A systematic review of COL1A1 splicing variants and the corresponding genotype–phenotype spectrum was performed. Results: Trio‐WES revealed a novel heterozygous variant in the C‐terminal region of the COL1A1 gene: NM_000088.4:c.3423+5G>A. Sanger sequencing confirmed the variant in both the proband (II‐2) and her foetus (III‐1) who were clinically suspected of having OI. The c.3423+5G>A variant causes complete skipping of Exon 46, as demonstrated by a minigene splicing assay. We retrieved 419 COL1A1 splicing variants from PubMed, excluded 15 without phenotypic data and 2 linked to Ehlers–Danlos syndrome and stratified the remaining 402 variants into three types on the basis of splice site location: (1) Variants at canonical splicing sites (77.8%, 313/402) mostly cause mild phenotypes, whereas a minority may be severe. (2) Intron variants in other locations, such as splice region variants (17.9%, 72/402), usually cause mild clinical phenotypes, and deep intronic splice variants (0.4%, 2/402) that may result in severe phenotypes. (3) Other variants (3.7%, 15/402), such as exon variants or fragment loss, are extremely rare. We also preliminarily discuss the mechanisms underlying phenotypic variability and the characteristics of C‐terminal variants. Conclusions: This intron variant in COL1A1 was classified as likely pathogenic and was confirmed to disrupt COL1A1 expression. The summary analysis results also revealed a correlation among splicing variants, C‐terminal region variants and disease, suggesting that variant location provides a useful framework for prognosis prediction.