A novel c.2179T>C mutation blocked the intracellular transport of PHEX protein and caused X-linked hypophosphatemic rickets in a Chinese family

Background

X‐linked hypophosphatemic rickets (XLH) is a heterogeneous genetic phosphate wasting disorder that occupies the majority of inheritable hypophosphatemic rickets (HR). XLH is caused by loss‐of‐function mutations in the phosphate‐regulating endopeptidase gene (PHEX) located on the X chromosome.

Method

In this study, we performed whole‐exome sequencing (WES) on the proband to identify the causative gene. The mutations were analyzed by predictive online software, such as PolyPhen‐2. Plasmids containing the wild‐type (WT) and mutant cDNA of the candidate gene were transfected into HEK293, then, the expression, cellular localization, and glycosylation state of the candidate proteins were detected by western blot, immunostaining, and endoglycosidase H digestion. The expression and concentration of related factor were measured by RT‐PCR and ELISA.

Results

We identified a novel missense mutation c.2179T>C in the PHEX that results in the substitution of p.Phe727Leu (F727L). This mutation was predicted to be disease‐causing by all four predictive online software. In vitro studies demonstrated that the F727L substitution hindered the intracellular trafficking of the mutant PHEX, with ~59% of mutant PHEX protein retained in the endoplasmic reticulum (ER) and only ~16% of the mutant protein localized on the cell surface. Endoglycosidase H digestion assay showed that the mutant F727L PHEX protein was not fully glycosylated. The concentration of intact FGF23 in hFOB1.19 cell culture medium collected from the mutant PHEX group was the highest (62.9 pg/ml) compared to the WT group (32.1 pg/ml) and control group (23.5 pg/ml).

Conclusion

Our results confirmed that the mutant PHEX protein was lowly glycosylated and retarded within the ER, the intact FGF23 level in cell culture media caused by the mutant PHEX protein was significantly elevated compared to that of the WT group, which may explain why the single base mutation in the PHEX led to XLH syndrome in this family.

Effect of PDGF-Rb antagonist imatinib on endometrial injury repairing in mouse model

OBJECTIVE

To study the effects of PDGF-Rb antagonists imatinib on endometrial injury repairing in the mouse model.

METHODS

The cultured MSCs cells from male mice were marked with BrdU in vitro, and then transplanted to the female mice which suffered from radiation injury through tail vein, PDGF-Rb antagonists imatinib was injected through abdominal cavity. Four groups were arranged, which were radiation transplantation group, normal control group, imatinib intervention group and radiation control group. BrdU incorporation, SRY expression and MVD status were detected in uterus of mice.

RESULTS

SRY gene was negative expressed in normal control group and radiation control group. SRY gene presented positive in radiation transplantation group and imatinib intervention group; BrdU incorporation showed negative in radiation control group and normal control group which died in the early stage in mice; the incorporation of BrdU was higher in radiation transplantation group compared with imatinib intervention group; CD34 was positive on the uterus of all the four groups, which showed highest in radiation control group and lowest in radiation control group; The MVD in imatinib intervention group was lower than radiation control group; the difference of MVD was significantly compared with normal control group (P < 0.05).

CONCLUSIONS

PDGF-Rb antagonists imatinib could inhibit the repairing function of MSCs in the endometrial lesions in mice.

Clinical application of operative hysteroscopy in treatment of complex hydrosalpinx prior to IVF

BACKGROUND

In vitro fertilization and embryo transfer (IVF-ET) is the best option for patients with hydrosalpinx. However, if hydrosalpinges is not pre-treated, the therapeutic outcomes of IVF-ET would be compromised.

OBJECTIVE

This study aims to investigate the safety and effects of operative hysteroscopy in the treatment of patients with hydrosalpinx prior to IVF-ET, who were not indicated for laparotomy due to extensive pelvic adhesion.

MATERIALS AND METHODS

The study analyses retrospectively data from 10 women with hydrosalpinx, who were unable to undergo laparotomy due to extensive pelvic adhesion and treated by operative hysteroscopy prior to IVF-ET, and was assessed the effects and safety of the procedure.

RESULTS

Postoperative Hystero-salpingography demonstrated complete tubal occlusion of the diseased side in all cases. Being applied with IVF-ET for fertility after their hysteroscopy operation, 5 out of 10 patients acquired clinical pregnancy.

CONCLUSION

Hysteroscopic tubal occlusion of the proximal part of the hydrosalpinx can effectively prevent the hydrops backflow to endometrial cavity and benefit subsequent implantation in the course of assisted reproduction without significant complications.

Adoptive transfer of pregnancy-induced CD4+CD25+ regulatory T cells reverses the increase in abortion rate caused by interleukin 17 in the CBA/JxBALB/c mouse model

STUDY QUESTION

Could adoptive transfer of pregnancy-induced CD4+CD25+ regulatory T cells (Tregs) reverse the increase in abortion rate caused by interleukin 17 (IL-17) in the CBA/J × BALB/c mouse model?

SUMMARY ANSWER

The effects of exogenous IL-17 on increased abortion rate, as well as decreased transforming growth factor (TGF)-β and IL-10 expression, are reversed by a pre-mating transfusion of Tregs in a mouse model of pregnancy.

WHAT IS KNOWN ALREADY

IL-17 is a pro-inflammatory cytokine mainly expressed by T helper 17 cells, and plays a pivotal role in the pathogenesis of endometriosis, miscarriage, preterm labor and pre-eclampsia. The activity of Th17 cells is attenuated by the anti-inflammatory action of Tregs.

STUDY DESIGN, SIZE, DURATION

Fifty microliters of phosphate-buffered saline (PBS) (Group 1,) or recombinant IL-17 (rIL) (10 µg/mouse) supernatant (Group 2) was administered in the vaginal vaults of anesthetized pregnant CBA/J mice on Day 1 of pregnancy. Tregs (2 × 10(5) cells) purified from pregnant CBA/J × BALB/c mice were given i.v. via the tail vein 2 days before mating (Group 3) or on Day 7 of pregnancy (Group 4).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Mice (n = 40) were randomly assigned to one of four experimental groups. The numbers of surviving and reabsorbed fetuses in each group were counted on Day 14 of pregnancy, and the expression of interferon (IFN)-γ, IL-4, TGF-β and IL-10 in the decidual tissue was assessed by real-time RT-PCR and western blotting.

MAIN RESULTS AND THE ROLE OF CHANCE

Normal pregnant CBA/J mice mated with BALB/c males which received transvaginal rIL-17 presented with a significantly increased abortion rate compared with the group which received PBS (27.7 versus 9.9%, respectively; P < 0.05). The transfusion of pregnancy-induced Tregs from 14-day normal pregnant mice 2 days before mating reduced the abortion rate caused by IL-17 (12.5 versus 27.7%, respectively; P < 0.05), while transfusion of Tregs on Day 7 of pregnancy had no effect. Transfusion of Tregs did not affect IFN-γ or IL-4 expression in the decidual tissue at either the mRNA or protein level. Administration of rIL-17 resulted in a decrease in production of TGF-β and IL-10 at both mRNA and protein levels (P < 0.05). Transfusion of Tregs before mating increased TGF-β and IL-10 mRNA and protein levels (P < 0.05), while Tregs transfusion at Day 7 of pregnancy had no effect on TGF-β or IL-10 expression.

LIMITATIONS, REASONS FOR CAUTION

These data derive from only a small number of mice. It is unclear whether the same effects would be seen in humans.

WIDER IMPLICATIONS OF THE FINDINGS

Abnormally elevated expression of IL-17 in the feto-maternal interface may result in miscarriage. Transfer of antigen-specific Tregs before mating takes place may have potential applications in the prevention of recurrent spontaneous abortion.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by a grant from the National Natural Science Foundation of China (81370013, 81000277 and 81300533) and Shandong Provincial Natural Science Foundation, China (ZR2013HQ002). There were no conflicts of interest.

Evaluation of association between the CYP11alpha promoter pentannucleotide (TTTTA)n polymorphism and polycystic ovarian syndrome among Han Chinese women

Evidence indicates that CYP11alpha is a positional and functional candidate for genetic study in polycystic ovarian syndrome (PCOS). In the present study, we have evaluated the association between the CYP11alpha promoter pentannucleotide (tttta)n polymorphism and PCOS among Han Chinese women. Subjects include 125 patients with PCOS and 121 healthy controls, and all were Han Chinese women. Clinical characteristics of patients with PCOS and control subjects were examined according to the Rotterdam consensus criteria. The CYP11alpha promoter pentannucleotide (tttta)n polymorphism was genotyped with PCR and fluorescent capillary electrophoresis protocol. Results indicate that common alleles of the CYP11alpha promoter pentannucleotide (tttta)n polymorphism in this population of Han Chinese women were P4, P6 and P8, and allele P6 was the most common one. Frequencies of those three common alleles between PCOS cases and controls (24.8, 65.6, 6.8% and 23.6, 65.7, 9.9%, respectively) were similar. No significant allelic association of this polymorphism with PCOS was found. However, the carriers with allele P6 among patients with PCOS had increased WHR (0.85+/-0.05 vs 0.82+/-0.08, P=0.039) and decreased AUCG (9.5+/-2.1 vs 11.4+/-2.8, P=0.021) compared to the patients carrying other alleles. Therefore, the most common allele of the CYP11alpha promoter pentannucleotide (tttta)n polymorphism in the population of Han Chinese women is P6, while the most common allele in European Caucasians, as previously reported, is P4. This polymorphism is an ethnic and racial variant, and may have the risk susceptibility in abnormal metabolism of patients with PCOS in Han Chinese women.