Cyclophilin A supports translation of intrinsically disordered proteins and affects haematopoietic stem cell ageing.

Loss of protein function is a driving force of ageing. We have identified peptidyl-prolyl isomerase A (PPIA or cyclophilin A) as a dominant chaperone in haematopoietic stem and progenitor cells. Depletion of PPIA accelerates stem cell ageing. We found that proteins with intrinsically disordered regions (IDRs) are frequent PPIA substrates. IDRs facilitate interactions with other proteins or nucleic acids and can trigger liquid-liquid phase separation. Over 20% of PPIA substrates are involved in the formation of supramolecular membrane-less organelles. PPIA affects regulators of stress granules (PABPC1), P-bodies (DDX6) and nucleoli (NPM1) to promote phase separation and increase cellular stress resistance. Haematopoietic stem cell ageing is associated with a post-transcriptional decrease in PPIA expression and reduced translation of IDR-rich proteins. Here we link the chaperone PPIA to the synthesis of intrinsically disordered proteins, which indicates that impaired protein interaction networks and macromolecular condensation may be potential determinants of haematopoietic stem cell ageing.

Does prophylactic antibiotics post pediatric pyeloplasty reduce the incidence of febrile UTIs?

PURPOSE: The use of postoperative prophylactic antibiotics in pediatric upper urinary tract reconstruction remains controversial. In this study, we examined whether low dose antibiotics administered following pediatric pyeloplasty reduce the incidence of febrile urinary tract infections at our institution. As a secondary outcome, in those patients with infection, additional analysis was performed to better quantify which patient population benefits the most from low dose prophylactic antibiotics. METHODS: Institutional review board approval (IRB) was obtained. All methods were carried out in accordance with relevant guidelines and regulations. A retrospective study was performed in patients who underwent pyeloplasty (2011-2017) at our institution. Surgical approach (laparoscopic versus robotic assisted versus open, with or without internal JJ ureteral stent) were based on surgeon preference. Patients of 8 fellowship trained pediatric urologists were included in the study period. Patients with prior history of urologic interventions or other congenital genitourinary tract abnormalities were excluded. Demographics (age, gender, ethnicity, insurance status), prior history of culture proven urinary tract infection, surgical details (administration of perioperative antibiotics), and postoperative outcomes including; 1) re-admission 30 days post-surgery, 2) any urine cultures collected due to suspected urinary tract infection. RESULTS: A total of 209 patients (149 boys, 60 girls) met our inclusion criteria with 55/209 (26%) receiving postoperative prophylactic antibiotics. The average age was 6 years (range: 2 months-18 years). Indwelling ureteral stent was used in 176 (84%) patients. Eleven patients (5%) had a culture-proven urinary tract infection within 30-days postoperatively. No significant differences were seen in postoperative complications or incidence of urinary tract infection when comparing surgical approaches, +/- ureteral stent, or the use of antibiotics. Secondary analysis noted statistically significant increase in post-operative urinary tract infection in younger children (2.8 v. 6.2 years, p = 0.02), those patients who had a positive preoperative urine culture (8/11, p = 0.01) and those with public health insurance (p = 0.038). CONCLUSION: The incidence of postoperative urinary tract infection following pyeloplasty in our cohort was relatively low. There was a higher incidence of urinary tract infection in patients less than 3 years old. The use of antibiotics in patients post pyeloplasty did not appear to affect the incidence of post-operative urinary tract infection, however, they may have a role in children who have not yet potty trained and in patients with positive preoperative urine culture.

Complete Genome Sequence of the Treponema pallidum subsp. pallidum Sea81-4 Strain.

Using the rabbit model of syphilis, the Sea81-4 strain of Treponema pallidum subsp. pallidum has been found to be more likely than other strains to invade the central nervous system (CNS). To identify possible explanations for this important phenotype at the genomic level, we sequenced the Sea81-4 strain genome.