Reduced expression of MECP2

MECP2 protein binds preferentially to methylated CpGs and regulates gene expression by causing changes in chromatin structure. The mechanism by which impaired MECP2 activity can induce pathological abnormalities in the nervous system of patients with Rett syndrome (RTT) is not clearly understood. To gain further insight into the role of MECP2 in human neurogenesis, we compared the neural differentiation process in mesenchymal stem cells (MSCs) obtained from a RTT patient and from healthy donors. We further analyzed neural differentiation in a human neuroblastoma cell line carrying a partially silenced MECP2 gene. Senescence and reduced expression of neural markers were observed in proliferating and differentiating MSCs from the RTT patient, which suggests that impaired activity of MECP2 protein may impair neural differentiation, as observed in RTT patients. Next, we used an inducible expression system to silence MECP2 in neuroblastoma cells before and after the induction of neural differentiation via retinoic acid treatment. This approach was used to test whether MECP2 inactivation affected the cell fate of neural progenitors and/or neuronal differentiation and maintenance. Overall, our data suggest that neural cell fate and neuronal maintenance may be perturbed by senescence triggered by impaired MECP2 activity either before or after neural differentiation

Effectiveness of Interventions Promoting HIV Serostatus Disclosure to Sexual Partners: A Systematic Review

Disclosure of HIV serostatus to sexual partners is mandated within certain states in the United States and other countries. Despite these laws implemented and public health efforts to increase disclosure, rates of disclosure to sexual partners among people living with HIV (PLWH) remain low, suggesting the need for interventions to assist PLWH with the disclosure process. We conducted a systematic review of studies testing whether HIV serostatus disclosure interventions increase disclosure to sexual partners. We searched six electronic databases and screened 484 records. Five studies published between 2005 and 2012 met inclusion criteria and were included in this review. Results showed that three of the HIV serostatus disclosure-related intervention studies were efficacious in promoting disclosure to sexual partners. Although all three studies were conducted in the United States the intervention content and measurements of disclosure across the studies varied, so broad conclusions are not possible. The findings suggest that more rigorous HIV serostatus disclosure-related intervention trials targeting different populations in the United States and abroad are needed to facilitate disclosure to sexual partners