The SUMOylation Pathway Restricts Gene Transduction by Adeno-Associated Viruses.

Adeno-associated viruses are members of the genus dependoviruses of the parvoviridae family. AAV vectors are considered promising vectors for gene therapy and genetic vaccination as they can be easily produced, are highly stable and non-pathogenic. Nevertheless, transduction of cells in vitro and in vivo by AAV in the absence of a helper virus is comparatively inefficient requiring high multiplicity of infection. Several bottlenecks for AAV transduction have previously been described, including release from endosomes, nuclear transport and conversion of the single stranded DNA into a double stranded molecule. We hypothesized that the bottlenecks in AAV transduction are, in part, due to the presence of host cell restriction factors acting directly or indirectly on the AAV-mediated gene transduction. In order to identify such factors we performed a whole genome siRNA screen which identified a number of putative genes interfering with AAV gene transduction. A number of factors, yielding the highest scores, were identified as members of the SUMOylation pathway. We identified Ubc9, the E2 conjugating enzyme as well as Sae1 and Sae2, enzymes responsible for activating E1, as factors involved in restricting AAV. The restriction effect, mediated by these factors, was validated and reproduced independently. Our data indicate that SUMOylation targets entry of AAV capsids and not downstream processes of uncoating, including DNA single strand conversion or DNA damage signaling. We suggest that transiently targeting SUMOylation will enhance application of AAV in vitro and in vivo.

Impact of pulmonary vein isolation on obstructive sleep apnea in patients with atrial fibrillation.

BACKGROUND: Obstructive sleep apnea (OSA) has been identified as associated with the onset and propagation of atrial fibrillation (AF) and predicts recurrences of AF after pulmonary vein isolation (PVI). Vice versa, it has never been investigated whether PVI influences OSA. However, it has been controversial whether a restored atrial function can affect the course of OSA. There-fore, we have assessed whether PVI procedure modulates the prevalence and severity of OSA. METHODS AND RESULTS: We included 23 individuals with AF that were assigned to undergo PVI into this study. Patients were 65 ± 7 years old, obese (BMI 29.9 ± 5.4 kg/m²), white (100%) and had a normal left ventricular function (LVEF 64 ± 9%). Polygraphic assessment was carried out before and 6 months after PVI. The prevalence of OSA, defined as an apnea-hypopnea index (AHI) ≥ 5 per hour of sleep, was 74% before PVI compared to 70% 6 months after the procedure (p > 0.05). Severity of OSA did not differ (AHI before vs. after: 18 ± 18/h vs. 15 ± 17/h, p > 0.05) as well as further polygraphic parameters did not differ before and after the procedure. CONCLUSIONS: Prevalence and severity of OSA are not affected by PVI in patients suffering from AF.

Gastroschisis and omphalocele: treatments and long-term outcomes.

Between February 1994 and April 2004, we treated 40 children with gastroschisis and 26 children with omphalocele. We recorded the course of pregnancy, pre- and post-natal complications, delivery, operation, post-operative therapy, and long-term outcomes. Additionally, we conducted follow-up examinations of 37 of these 66 children (56%). We analysed their abdominal musculature, development, cosmetic result and quality of life. The median duration of follow-up was 6.3 years (range 1-10). In 35/40 children (88%) with gastroschisis and in 18/26 children (69%) with omphalocele, there had been prenatal diagnosis. The average maternal age of 23.9 years in the gastroschisis group was lower than in the omphalocele group (29.9 years). Delivery was by caesarean section in 93% of the gastroschisis group and 65% of the omphalocele group. Outcomes following vaginal delivery were no worse than those after caesarean section. Further, congenital abnormalities were shown in 28% of gastroschisis cases, and were limited to the gastrointestinal tract. Of the omphalocele cases 81% showed further abnormalities. Direct closure of the abdominal wall defect was possible in 31/40 (78%) of the gastroschisis cases and 15/26 (58%) of the omphalocele cases. Mortality in gastroschisis was nil; two children with omphalocele died (8%). Outcomes were better after primary closure than in stepwise reconstruction. Follow-up showed good results in all categories. Developmental delays were rapidly made up after treatment, and 75% of the children had no gastrointestinal problems, or suffered from these rarely. Almost all the children were of normal weight and height, and physical and intellectual development were delayed in only one third of the children. The surgical scar was rated as good or very good in about 80% of the cases. Except for those with severe defects, the children had good ratings for quality of life. Improvements in short-term results of gastroschisis and omphalocele treatment can be attributed to recent developments in prenatal diagnosis and the advancements of centralised perinatal care. Our long-term results clearly demonstrate that initial gastrointestinal problems and developmental delays were made up during the first two years of life. Prenatal counselling can now be more optimistic.