Target-derived neurotrophins coordinate transcription and transport of bclw to prevent axonal degeneration.

Establishment of neuronal circuitry depends on both formation and refinement of neural connections. During this process, target-derived neurotrophins regulate both transcription and translation to enable selective axon survival or elimination. However, it is not known whether retrograde signaling pathways that control transcription are coordinated with neurotrophin-regulated actions that transpire in the axon. Here we report that target-derived neurotrophins coordinate transcription of the antiapoptotic gene bclw with transport of bclw mRNA to the axon, and thereby prevent axonal degeneration in rat and mouse sensory neurons. We show that neurotrophin stimulation of nerve terminals elicits new bclw transcripts that are immediately transported to the axons and translated into protein. Bclw interacts with Bax and suppresses the caspase6 apoptotic cascade that fosters axonal degeneration. The scope of bclw regulation at the levels of transcription, transport, and translation provides a mechanism whereby sustained neurotrophin stimulation can be integrated over time, so that axonal survival is restricted to neurons connected within a stable circuit.

Improving Pediatric Ovarian Torsion Evaluation in the Pediatric Emergency Department: A Quality Improvement Initiative.

Background: Transabdominal pelvic ultrasound (TPUS) is the diagnostic test of choice for the evaluation of ovarian torsion, a time-sensitive surgical emergency. A full bladder is required to visualize the ovaries. Bladder filling is a time-consuming process leading to delays to TPUS, poor visualization of ovaries requiring repeat studies, and prolonged emergency department length of stay (ED LOS). The primary objective was to decrease the time to TPUS by standardizing the bladder filling process. Methods: This quality improvement initiative occurred at a single, academic, quaternary-care children's hospital ED and utilized the Institute for Healthcare Improvement Model for Improvement with sequential plan-do-study-act cycles. The first set of interventions implemented in August 2021 included a new electronic order set and bladder scan by ED nurses. Subsequent plan-do-study-act cycles aimed to decrease the time to intravenous fluid, decrease fluid requirement, and decrease the need for intravenous fluid. The primary outcome measure was the monthly mean time to TPUS. Secondary outcome measures included monthly mean ED LOS and percentage of repeat TPUS. We performed data analysis with statistical process control charts to assess for system change over time. Results: The preintervention baseline included 292 ED encounters more than 10 months, and postintervention analysis included 526 ED encounters more than 16 months. Time to TPUS decreased (138-120 min), ED LOS decreased (372-335 min), and repeat TPUS decreased (18% to 4%). All changes met the rules for special cause variation. Conclusions: Standardizing the bladder filling process was associated with decreased time to TPUS, ED LOS, and repeat TPUS.

Improving and Sustaining Interpreter Use Over 5 Years in a Pediatric Emergency Department.

BACKGROUND: Patients with a language for care other than English (LOE) face communication barriers and inequitable outcomes in health care. Professional interpretation can improve outcomes but is underutilized. Our pediatric emergency department (ED) implemented quality improvement (QI) interventions over a 5-year period with an aim to increase interpreter use to 80% of patient encounters with LOE. METHODS: Overall interpreter use for ED encounters was measured over time, with a baseline period of October 2015 to December 2016 and during 5 years of QI interventions from January 2017 to August 2021. Interventions included staff education, data feedback, reducing barriers to interpreter use, and improving identification of language for care with plan-do-study-act cycles. Outcomes were analyzed by using statistical process control charts and standard rules for special cause variation. RESULTS: We analyzed a total of 277 309 ED encounters during the study period, 12.2% with LOE. The overall use of interpretation increased from a baseline of 53% to 82% of encounters. Interpretation throughout the ED visit and the number of interpreted interactions per hour also increased. There was improvement across language types, patient age groups, acuity levels, and during different times of day. Special cause variation was associated with multiple QI interventions. CONCLUSION: We reached our primary aim of providing professional interpretation for 80% of patient encounters with LOE. There were several QI interventions associated with improvements, including staff education, data feedback, improved access to interpretation, and improved identification and visualization of language for care. Efforts to improve interpreter use may benefit from a similar multifaceted approach.

Differentiating human multipotent mesenchymal stromal cells regulate microRNAs: prediction of microRNA regulation by PDGF during osteogenesis.

OBJECTIVE: Human multipotent mesenchymal stromal cells (MSC) have the potential to differentiate into multiple cell types, although little is known about factors that control their fate. Differentiation-specific microRNAs may play a key role in stem cell self-renewal and differentiation. We propose that specific intracellular signaling pathways modulate gene expression during differentiation by regulating microRNA expression. MATERIALS AND METHODS: Illumina mRNA and NCode microRNA expression analyses were performed on MSC and their differentiated progeny. A combination of bioinformatic prediction and pathway inhibition was used to identify microRNAs associated with platelet-derived growth factor (PDGF) signaling. RESULTS: The pattern of microRNA expression in MSC is distinct from that in pluripotent stem cells, such as human embryonic stem cells. Specific populations of microRNAs are regulated in MSC during differentiation targeted toward specific cell types. Complementary mRNA expression analysis increases the pool of markers characteristic of MSC or differentiated progeny. To identify microRNA expression patterns affected by signaling pathways, we examined the PDGF pathway found to be regulated during osteogenesis by microarray studies. A set of microRNAs bioinformatically predicted to respond to PDGF signaling was experimentally confirmed by direct PDGF inhibition. CONCLUSION: Our results demonstrate that a subset of microRNAs regulated during osteogenic differentiation of MSCs is responsive to perturbation of the PDGF pathway. This approach not only identifies characteristic classes of differentiation-specific mRNAs and microRNAs, but begins to link regulated molecules with specific cellular pathways.

Paclitaxel Reduces Axonal Bclw to Initiate IP3R1-Dependent Axon Degeneration.

Chemotherapy-induced peripheral neuropathy (CIPN) is a debilitating side effect of many cancer treatments. The hallmark of CIPN is degeneration of long axons required for transmission of sensory information; axonal degeneration causes impaired tactile sensation and persistent pain. Currently the molecular mechanisms of CIPN are not understood, and there are no available treatments. Here we show that the chemotherapeutic agent paclitaxel triggers CIPN by altering IP3 receptor phosphorylation and intracellular calcium flux, and activating calcium-dependent calpain proteases. Concomitantly paclitaxel impairs axonal trafficking of RNA-granules and reduces synthesis of Bclw (bcl2l2), a Bcl2 family member that binds IP3R1 and restrains axon degeneration. Surprisingly, Bclw or a stapled peptide corresponding to the Bclw BH4 domain interact with axonal IP3R1 and prevent paclitaxel-induced degeneration, while Bcl2 and BclxL cannot do so. Together these data identify a Bclw-IP3R1-dependent cascade that causes axon degeneration and suggest that Bclw-mimetics could provide effective therapy to prevent CIPN.

The RNA-binding protein SFPQ orchestrates an RNA regulon to promote axon viability.

To achieve accurate spatiotemporal patterns of gene expression, RNA-binding proteins (RBPs) guide nuclear processing, intracellular trafficking and local translation of target mRNAs. In neurons, RBPs direct transport of target mRNAs to sites of translation in remote axons and dendrites. However, it is not known whether an individual RBP coordinately regulates multiple mRNAs within these morphologically complex cells. Here we identify SFPQ (splicing factor, poly-glutamine rich) as an RBP that binds and regulates multiple mRNAs in dorsal root ganglion sensory neurons and thereby promotes neurotrophin-dependent axonal viability. SFPQ acts in nuclei, cytoplasm and axons to regulate functionally related mRNAs essential for axon survival. Notably, SFPQ is required for coassembly of LaminB2 (Lmnb2) and Bclw (Bcl2l2) mRNAs in RNA granules and for axonal trafficking of these mRNAs. Together these data demonstrate that SFPQ orchestrates spatial gene expression of a newly identified RNA regulon essential for axonal viability.