Endometrial mesenchymal stromal/stem cells improve regeneration of injured endometrium in mice

BACKGROUND: The monthly regeneration of human endometrial tissue is maintained by the presence of human endometrial mesenchymal stromal/stem cells (eMSC), a cell population co-expressing the perivascular markers CD140b and CD146. Endometrial regeneration is impaired in the presence of intrauterine adhesions, leading to infertility, recurrent pregnancy loss and placental abnormalities. Several types of somatic stem cells have been used to repair the damaged endometrium in animal models, reporting successful pregnancy. However, the ability of endometrial stem cells to repair the damaged endometrium remains unknown. METHODS: Electrocoagulation was applied to the left uterine horn of NOD/SCID mice causing endometrial injury. Human eMSC or PBS was then injected into the left injured horn while the right normal horn served as controls. Mice were sacrificed at different timepoints (Day 3, 7 and 14) and the endometrial morphological changes as well as the degree of endometrial injury and repair were observed by histological staining. Gene expression of various inflammatory markers was assessed using qPCR. The functionality of the repaired endometrium was evaluated by fertility test. RESULTS: Human eMSC successfully incorporated into the injured uterine horn, which displayed significant morphological restoration. Also, endometrium in the eMSC group showed better cell proliferation and glands formation than the PBS group. Although the number of blood vessels were similar between the two groups, gene expression of VEGF-α significantly increased in the eMSC group. Moreover, eMSC had a positive impact on the regeneration of both stromal and epithelial components of the mouse endometrium, indicated by significantly higher vimentin and CK19 protein expression. Reduced endometrial fibrosis and down-regulation of fibrosis markers were also observed in the eMSC group. The eMSC group had a significantly higher gene expression of anti-inflammatory factor Il-10 and lower mRNA level of pro-inflammatory factors Ifng and Il-2, indicating the role of eMSC in regulation of inflammatory reactions. The eMSC group showed higher implantation sites than the PBS group, suggesting better endometrial receptivity with the presence of newly emerged endometrial lining. CONCLUSIONS: Our findings suggest eMSC improves regeneration of injured endometrium in mice.

Nucleotide sequence polymorphism in the RFL-PPR genes of potato

Cytoplasmic male sterility (CMS) is widely used for hybrid seed production in cultivated Solanaceae species. However, there is very limited information about CMS-Rf genetic systems in potato (Solanum tuberosum). Studying the CMS-Rf systems in potato is both of theoretical and practical significance due to the emergence of a new revolutionary strategy of reinventing potato as adiploid inbred line-based crop to develop F1 hybrid seed potato breeding (Lindhout et al. 2011; Jansky et al. 2016). To search for potato Rf gene candidates, the comparative genetic approach was applied. Based on similarity to petunia Rf-PPR592 gene, 38 fragments were identified in five loci of the whole-genome nucleotide sequence of the accession DM 1-3 516 R44 S. tuberosum Phureja group (https://blast.ncbi.nlm.nih.gov/Blast.cgi). The putative encoded mitochondrial proteins have 589–597 amino acid residues, similarto RF-PPR proteins of petunia and chili pepper and contain 14 or 15 PPR motifs. Primers have been developed flanking the most variable 782–865 bp regions of the selected loci, and polymorphism of the cloned fragments has been investigated in a subset of nine potato genotypes. The amplified fragments included seven or eight PPR motifs and lacked introns. The SNP frequencies ranged from 7.0 to 19.8% depending on the locus, while the ratio of nonsynonymous to synonymous substitutions varied between 0.9 and 2.1.Positions 1, 3 and 6 were the most variable in the studied PPR motifs. Our results demonstrated that the analysed sequences belong to the RFL-PPR gene subfamily and may be considered as Rf gene candidates in potato.