Epigenetic changes as a common trigger of muscle weakness in congenital myopathies

Congenital myopathies are genetically and clinically heterogeneous conditions causing severe muscle weakness, and mutations in the ryanodine receptor gene (RYR1) represent the most frequent cause of these conditions. A common feature of diseases caused by recessive RYR1 mutations is a decrease of ryanodine receptor 1 protein content in muscle. The aim of the present investigation was to gain mechanistic insight into the causes of this reduced ryanodine receptor 1. We found that muscle biopsies of patients with recessive RYR1 mutations exhibit decreased expression of muscle-specific microRNAs, increased DNA methylation and increased expression of class II histone deacetylases. Transgenic mouse muscle fibres over-expressing HDAC-4/HDAC-5 exhibited decreased expression of RYR1 and of muscle-specific miRNAs, whereas acute knock-down of RYR1 in mouse muscle fibres by siRNA caused up-regulation of HDAC-4/HDAC-5. Intriguingly, increased class II HDAC expression and decreased ryanodine receptor protein and miRNAs expression were also observed in muscles of patients with nemaline myopathy, another congenital neuromuscular disorder. Our results indicate that a common pathophysiological pathway caused by epigenetic changes is activated in some forms of congenital neuromuscular disorder

Tumor necrosis factor alpha expression is increased in maternal microvascular endothelial cells in preeclampsia

Objective: The aim of this study was to explore the expression and effects of tumor necrosis factor alpha (TNFα) in maternal endothelial cells in preeclampsia (PE). Methods: Expression levels in primary microvascular endothelial cells (MVEC) isolated from patients with severe preeclampsia (PE) and normal pregnancies were determined by RT-qPCR with or without treatment of TNFα and inhibitors for downstream signaling. Results: PE MVEC exhibited increased basal TNFα expression. TNFα treatment increased TNFα, VCAM, and endocan expression in MVEC. Conclusion: TNFα expression is increased in PE MVEC and the treatment of these cells with exogenous TNFα modifies their gene expression

The effect of magnesium sulfate on gene expression in maternal microvascular endothelial cells

Preeclampsia is a severe complication of pregnancy associated with maternal and fetal morbidity and mortality. To date, magnesium sulfate remains the preferred method of treatment used to reduce the development of eclampsia. Our aim was to investigate the effects of magnesium sulfate on the expression of genes involved with endothelial function in maternal microvascular endothelial cells from both normal and preeclamptic pregnancies. Primary cells from normal pregnancies treated with 80 mg/L magnesium sulfate for 6 h revealed an overall trend of increased expression of angiogenic and vasopressor-related factors by qPCR analyses. Primary cells from preeclamptic pregnancies revealed an overall trend of decreased expression, with significantly lowered levels for vascular endothelial growth factor receptor 2, endothelin, and vascular cell adhesion protein-1. A comparison of treated cells revealed significantly increased levels for endoglin, vascular endothelial growth factor receptor 2, soluble fms-like tyrosine kinase-1, prostacyclin synthase, tumor necrosis factor α, tumor necrosis factor receptor 1, and endothelin in normal versus preeclamptic cells following treatment. These results reveal disparate activation of overall expression activity by magnesium sulfate in maternal endothelial cells from normal pregnancies over preeclamptic pregnancies

Attenuation of VEGFR-2 expression by sFlt-1 and low oxygen in human placenta.

Vascular endothelial growth factor receptor 2 (VEGFR-2), the primary receptor for VEGF, is crucial for normal endothelial function. sFlt-1, a truncated and soluble form of VEGFR-1 which binds and inhibits VEGF, is increased in preeclampsia and is positively regulated by low oxygen. Here, we investigated the effects of sFlt-1 and hypoxia on VEGFR-2 expression and signaling in the human placenta. VEGFR-2 transcript and protein levels were significantly decreased in preeclamptic placentae compared to controls (1.82 and 1.85 fold, respectively). An inverse correlation was observed for VEGFR-2 and sFlt-1 levels in both singleton and twin placentae from patients with preeclampsia. Immunofluorescence analyses revealed co-localization of VEGFR-2 and sFlt-1 in placental vasculature and co-immunoprecipitation analyses confirmed VEGFR-2 and sFlt-1 interaction only in preeclamptic placentae compared to age-matched controls. VEGFR-2 transcript and protein levels from explants cultured in 3% O2 were significantly decreased compared to those incubated at 20% O2 (5.9 and 12.47 fold, respectively). Also, VEGFR-2 transcript levels were significantly decreased in early first trimester placentae (low oxygen environment) compared to late first trimester placentae (2.05 fold). We next explored whether sFlt-1 directly affects VEGFR-2 expression. Treatment of first trimester placental explants with sFlt-1 resulted in significantly decreased levels of VEGFR-2 (2.03 fold) and downstream signaling proteins phospho-ERK (1.60 fold) and phospho-Akt (1.64 fold). Our findings show a novel hypoxia-induced and PE-related down-regulation of VEGFR-2 in the human placenta. sFlt-1, which is known to be increased in hypoxic conditions and PE, directly attenuates VEGFR-2 expression and signaling. A direct interaction between sFlt-1 and VEGFR-2 may represent an important mechanism in VEGFR-2 regulation, inhibition of VEGFR-2-mediated processes in placentation and a novel platform to examine the onset of preeclampsia

Uterine Compression Sutures as an Effective Treatment for Postpartum Hemorrhage: Case Series

We evaluated the role of uterine compression sutures as a conservative treatment for postpartum hemorrhage (PPH) after failed medical treatment. We retrospectively reviewed the charts of all patients who delivered between 2003 and 2009 at a single tertiary care center and who underwent uterine compression sutures for PPH. Twelve women had uterine compression sutures for PPH. The mean age of the patients was 36.3 ± 5.2 years. The mean gestational age at delivery was 37.7 ± 2.0 weeks, and the average estimated blood loss was 2.1 ± 1.1 L. The mean procedure time to perform the uterine compression sutures was 9.3 ± 2.8 minutes. The success rate of compression sutures was 92% with only one failure resulting in a hysterectomy. Uterine compression sutures are an effective method for the treatment of PPH, thus avoiding hysterectomy and preserving potential fertility

Endometrial Thickness- a Practical Prospective Marker for the Risk of Surgical Intervention after RU486 Induced Abortion

Background Medical termination of pregnancy [TOP] during the early first trimester is commonly used. However, treatment failure which warrants surgical intervention occurs in small proportion of patients. Our objective was to examine the effectiveness and predictive value of sonographic measurement of endometrial thickness during a follow up visit after medical abortion as an accurate predictor of the necessity of curettage for completion of pregnancy termination. Methods Women who opted for medical TOP where treated by single dose of RU486 followed by a single dose of misoprostol. Endometrial thickness was evaluated by transvaginal U.S. at 14 days after misoprostol tretament. The data was collected prospectively for this cohort study which includes all the women undergoing medical abortion in the first seven weeks of gestation. Results In 34.7% of the patients the endometrial width was > 11 mm on the follow-up visit. Surgical intervention was performed in 18% of these patients, for a failure rate of the medical termination of pregnancy [TOP] of 6.25%, as compared with no failure rate in those with endometrium 12 mm the failure was 5.9%. In cases where the endometrium was 12-13 mm the failure rate was 27.3%, and if >13 mm the failure was 18.9%. When the endometrium was 13-14 mm the failure rate was 10%, and when >14 mm the failure was 23.7%. Half of the 18 patients who had undergone dilatation and curettage [D&C] for completion of the TOP, had endometrium > 14 mm, one to two weeks after the medical abortion. Conclusion Measurement of endometrial width after medical TOP is beneficial in segregating patient to low or high risk for surgical treatment of retained product of conception [POC]. Using a cutoff of 11 mm during the follow-up visit after medical TOP, 18% of the patients may need dilatation and curettage to complete the pregnancy termination, and if it is >14 mm, half of them may need surgical intervention. There is no difference between 11 and 14 mm regarding the risk of surgical intervention after medical TOP

Increased association of VEGFR-2 and sFlt-1 in preeclamptic placentae.

<p><b>A:</b> Representative sFlt-1 immunoblot of developmental placental samples (two different tissue samples at each gestational age of 8, 12 and 35 weeks) immunoprecipitated with a monoclonal VEGFR-2 antibody. A control lane of protein lysates prepared from placental tissue (35 weeks of gestation) is indicated (Input). <b>B:</b> Representative sFlt-1 immunoblot of PE and PTC samples immunoprecipitated with a monoclonal VEGFR-2 antibody. A negative control lane of PE protein lysate immunoprecipitated in the absence of VEGFR-2 antibody is indicated (NB). Densitometry analysis comparing sFlt-1 immunoreactivity between PE (n = 3) and PTC (n = 6) samples immunoprecipitated with VEGFR-2 antibody. (IP, immunoprecipitation antibody; WB, western blot antibody; PE, preeclampsia; PTC, age-matched preterm control; *<i>P</i><0.05). All values are represented as the means±SEM.</p