Dysregulation of the sensory and regulatory pathways controlling cellular iron metabolism in unilateral obstructive nephropathy.

Chronic kidney disease involves disturbances in iron metabolism including anemia caused by insufficient erythropoietin (EPO) production. However, underlying mechanisms responsible for the dysregulation of cellular iron metabolism are incompletely defined. Using the unilateral ureteral obstruction (UUO) model in Irp1+/+ and Irp1-/- mice, we asked if iron regulatory proteins (IRPs), the central regulators of cellular iron metabolism and suppressors of EPO production, contribute to the etiology of anemia in kidney failure. We identified a significant reduction in IRP protein level and RNA binding activity that associates with a loss of the iron uptake protein transferrin receptor 1 (TfR1), increased expression of the iron storage protein subunits H- and L-ferritin, and a low but overall variable level of stainable iron in the obstructed kidney. This reduction in IRP RNA binding activity and ferritin RNA levels suggests the concomitant rise in ferritin expression and iron content in kidney failure is IRP dependent. In contrast, the reduction in the Epo mRNA level in the obstructed kidney was not rescued by genetic ablation of IRP1, suggesting disruption of normal hypoxia-inducible factor (HIF)-2α regulation. Furthermore, reduced expression of some HIF-α target genes in UUO occurred in the face of increased expression of HIF-α proteins and prolyl hydroxylases 2 and 1, the latter of which is not known to be HIF-α mediated. Our results suggest that the IRP system drives changes in cellular iron metabolism that are associated with kidney failure in UUO but that the impact of IRPs on EPO production is overridden by disrupted hypoxia signaling.NEW & NOTEWORTHY This study demonstrates that iron metabolism and hypoxia signaling are dysregulated in unilateral obstructive nephropathy. Expression of iron regulatory proteins (IRPs), central regulators of cellular iron metabolism, and the iron uptake (transferrin receptor 1) and storage (ferritins) proteins they target is strongly altered. This suggests a role of IRPs in previously observed changes in iron metabolism in progressive renal disease. Hypoxia signaling is disrupted and appeared to dominate the action of IRP1 in controlling erythropoietin expression.

Transition care continuity promotes long-term retention in adult care among young adults with sickle cell disease.

BACKGROUND/OBJECTIVES: Care continuity prevents increased health care utilization and mortality during transition from pediatric to adult care. Our program employs a co-located care delivery model, in which pediatric provider involvement continues during young adulthood. We tested the hypothesis that individuals who participated in the co-located model have greater retention in adult care compared to those who only received pediatric transition services. METHODS: This study consisted of 311 youth with SCD (51.4% male; 63.0% HbSS/HbSß0 -thalassemia) who transferred to adult care from 2007 to 2017. Retention was defined as continuation with an adult provider for ≥12 or ≥24 months post-pediatric care. Logistic regression estimated the association between co-location status and retention at 12 and 24 months. Logistic regression and t-tests were used to evaluate potential predictors of retention in adult care. RESULTS: Individuals who participated in the co-location model were 1.9 times more likely to remain in adult care 12 (95% CI: 1.01, 3.47) and 24 (95% CI: 1.01, 3.70) months post-pediatric care compared to those who did not participate. Individuals with HbSS/HbSß0 -thalassemia were 1.9 times more likely to be retained at 12 months compared to those with HbSC/HbSß+ -thalassemia/HbS/HPFH (95% CI: 1.12, 3.09). For every clinic encounter in the last 2 years of pediatric care, the odds of being retained at least 24 months after initiating adult care increased 1.1 times (95% CI: 1.02, 1.13). CONCLUSIONS: Continuity of providers from pediatric to adult care may increase long-term retention in adult care. Longitudinal monitoring of adult outcomes is critical to identifying the efficacy of transition services.

The development, implementation and evaluation of clinical pathways for chronic obstructive pulmonary disease (COPD) in Saskatchewan: protocol for an interrupted times series evaluation.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) has substantial economic and human costs; it is expected to be the third leading cause of death worldwide by 2030. To minimize these costs high quality guidelines have been developed. However, guidelines alone rarely result in meaningful change. One method of integrating guidelines into practice is the use of clinical pathways (CPWs). CPWs bring available evidence to a range of healthcare professionals by detailing the essential steps in care and adapting guidelines to the local context. METHODS/DESIGN: We are working with local stakeholders to develop CPWs for COPD with the aims of improving care while reducing utilization. The CPWs will employ several steps including: standardizing diagnostic training, unifying components of chronic disease care, coordinating education and reconditioning programs, and ensuring care uses best practices. Further, we have worked to identify evidence-informed implementation strategies which will be tailored to the local context. We will conduct a three-year research project using an interrupted time series (ITS) design in the form of a multiple baseline approach with control groups. The CPW will be implemented in two health regions (experimental groups) and two health regions will act as controls (control groups). The experimental and control groups will each contain an urban and rural health region. Primary outcomes for the study will be quality of care operationalized using hospital readmission rates and emergency department (ED) presentation rates. Secondary outcomes will be healthcare utilization and guideline adherence, operationalized using hospital admission rates, hospital length of stay and general practitioner (GP) visits. Results will be analyzed using segmented regression analysis. DISCUSSION: Funding has been procured from multiple stakeholders. The project has been deemed exempt from ethics review as it is a quality improvement project. Intervention implementation is expected to begin in summer of 2017. This project is expected to improve quality of care and reduce healthcare utilization. In addition it will provide evidence on the effects of CPWs in both urban and rural settings. If the CPWs are found effective we will work with all stakeholders to implement similar CPWs in surrounding health regions. TRIAL REGISTRATION: Clinicaltrials.gov ( NCT03075709 ). Registered 8 March 2017.

THE QUALITY OF FATHER-CHILD ROUGH-AND-TUMBLE PLAY AND TODDLERS' AGGRESSIVE BEHAVIOR IN CHINA.

The purpose of this study was to explore the influence of the quality of early father-child rough-and-tumble play (RTP) on toddler aggressive behaviors and more fully understand how child, mother, and father characteristics were associated with higher quality father-child RTP among contemporary urban Chinese families. Participants included 42 families in Changsha, China. Play observations of fathers and their children were coded for RTP quality. The specific RTP quality of father-child reciprocity of dominance was associated with fewer toddler aggressive behaviors, as rated by both fathers and mothers. Mothers' democratic parenting attitudes were associated with higher quality father-child RTP. These findings suggest that higher quality father-child RTP may be one way in which some fathers influence children's expression of aggressive behaviors, and the quality of father-child RTP may be influenced by the broader family, social, and cultural contexts.

Low intracellular iron increases the stability of matriptase-2.

Matriptase-2 (MT2) is a type II transmembrane serine protease that is predominantly expressed in hepatocytes. It suppresses the expression of hepatic hepcidin, an iron regulatory hormone, by cleaving membrane hemojuvelin into an inactive form. Hemojuvelin is a bone morphogenetic protein (BMP) co-receptor. Here, we report that MT2 is up-regulated under iron deprivation. In HepG2 cells stably expressing the coding sequence of the MT2 gene, TMPRSS6, incubation with apo-transferrin or the membrane-impermeable iron chelator, deferoxamine mesylate salt, was able to increase MT2 levels. This increase did not result from the inhibition of MT2 shedding from the cells. Rather, studies using a membrane-permeable iron chelator, salicylaldehyde isonicotinoyl hydrazone, revealed that depletion of cellular iron was able to decrease the degradation of MT2 independently of internalization. We found that lack of the putative endocytosis motif in its cytoplasmic domain largely abolished the sensitivity of MT2 to iron depletion. Neither acute nor chronic iron deficiency was able to alter the association of Tmprss6 mRNA with polyribosomes in the liver of rats indicating a lack of translational regulation by low iron levels. Studies in mice showed that Tmprss6 mRNA was not regulated by iron nor the BMP-mediated signaling with no evident correlation with either Bmp6 mRNA or Id1 mRNA, a target of BMP signaling. These results suggest that regulation of MT2 occurs at the level of protein degradation rather than by changes in the rate of internalization and translational or transcriptional mechanisms and that the cytoplasmic domain of MT2 is necessary for its regulation.

Iron regulatory protein-1 protects against mitoferrin-1-deficient porphyria.

Mitochondrial iron is essential for the biosynthesis of heme and iron-sulfur ([Fe-S]) clusters in mammalian cells. In developing erythrocytes, iron is imported into the mitochondria by MFRN1 (mitoferrin-1, SLC25A37). Although loss of MFRN1 in zebrafish and mice leads to profound anemia, mutant animals showed no overt signs of porphyria, suggesting that mitochondrial iron deficiency does not result in an accumulation of protoporphyrins. Here, we developed a gene trap model to provide in vitro and in vivo evidence that iron regulatory protein-1 (IRP1) inhibits protoporphyrin accumulation. Mfrn1(+/gt);Irp1(-/-) erythroid cells exhibit a significant increase in protoporphyrin levels. IRP1 attenuates protoporphyrin biosynthesis by binding to the 5'-iron response element (IRE) of alas2 mRNA, inhibiting its translation. Ectopic expression of alas2 harboring a mutant IRE, preventing IRP1 binding, in Mfrn1(gt/gt) cells mimics Irp1 deficiency. Together, our data support a model whereby impaired mitochondrial [Fe-S] cluster biogenesis in Mfrn1(gt/gt) cells results in elevated IRP1 RNA-binding that attenuates ALAS2 mRNA translation and protoporphyrin accumulation.

F-box and leucine-rich repeat protein 5 (FBXL5) is required for maintenance of cellular and systemic iron homeostasis.

Maintenance of cellular iron homeostasis requires post-transcriptional regulation of iron metabolism genes by iron regulatory protein 2 (IRP2). The hemerythrin-like domain of F-box and leucine-rich repeat protein 5 (FBXL5), an E3 ubiquitin ligase subunit, senses iron and oxygen availability and facilitates IRP2 degradation in iron replete cells. Disruption of the ubiquitously expressed murine Fbxl5 gene results in a failure to sense increased cellular iron availability, accompanied by constitutive IRP2 accumulation and misexpression of IRP2 target genes. FBXL5-null mice die during embryogenesis, although viability is restored by simultaneous deletion of the IRP2, but not IRP1, gene. Mice containing a single functional Fbxl5 allele behave like their wild type littermates when fed an iron-sufficient diet. However, unlike wild type mice that manifest decreased hematocrit and hemoglobin levels when fed a low-iron diet, Fbxl5 heterozygotes maintain normal hematologic values due to increased iron absorption. The responsiveness of IRP2 to low iron is specifically enhanced in the duodena of the heterozygotes and is accompanied by increased expression of the divalent metal transporter-1. These results confirm the role of FBXL5 in the in vivo maintenance of cellular and systemic iron homeostasis and reveal a privileged role for the intestine in their regulation by virtue of its unique FBXL5 iron sensitivity.

Genetic education and sickle cell disease: feasibility and efficacy of a program tailored to adolescents.

Sickle cell disease (SCD) genetic knowledge is important when individuals make reproductive decisions. This study assessed feasibility and efficacy of delivering basic genetic information to 101 adolescents with SCD. Participants completed a questionnaire to test SCD genetic knowledge at 3 timepoints: before genetic education session (pretest), after the session (posttest), and 6 months later (follow-up). Scores at 3 timepoints were compared by Wilcoxon signed-rank tests, and group differences were compared by Wilcoxon-Mann-Whitney and Kruskal-Wallis tests. Participants' median scores significantly increased from pretest to posttest and from pretest to follow-up. Males had a greater change in scores than females. Scores decreased slightly from posttest to follow-up. Participants with HbSS/HbSß°-thal genotype and participants with more prior pain episodes exhibited a smaller increase in median scores than those with HbSC/HbSß⁺-thal genotype and no prior pain history; however, all groups had substantial gains from pretest to posttest and follow-up tests demonstrating that adolescents with SCD can learn basic genetics. This study established that genetic education can successfully be incorporated in transition to adult care programs for adolescents with SCD. Genetic education should be included in the standard plan of care for adolescents with SCD to assist them in making informed reproductive choices.

Gaps during Pediatric to Adult Care Transfer Escalate Acute Resource Utilization in Sickle Cell Disease.

Guidelines recommend transfer to adult healthcare within six months of completing pediatric care, however this has not been studied in sickle cell (SCD). We hypothesized that longer transfer gaps are associated with increased resource utilization. Transfer gaps were defined as the time between the last pediatric and first adult visits. We estimated the association between varying transfer gaps and the rate of inpatient, emergency department (ED), and outpatient visits using negative binomial regression. Healthcare utilization was evaluated in a mid-south comprehensive program for a follow-up period of up to eight years (2012-2020) and also restricted to the first two years of adult healthcare. In total, 183 young adults (YAs) with SCD (51% male, 67% HbSS/HbSß0-thalassemia) transferred to adult healthcare between 2012-2018. YAs with transfer gaps ≥6 months compared to <2 months had 2.01 (95%CI: 1.31, 3.11) times the rate of hospitalizations in the 8-year follow-up and 1.89 (95%CI: 1.17, 3.04) when restricted to the first two years of adult healthcare. In the first two years of adult care, those with transfer gaps ≥6 months compared to <2 months, had 1.75 (95%CI: 1.10, 2.80) times the rate of ED encounters. Those with gaps ≥2 to <6 months compared to <2 months had 0.71 (95%CI: 0.53, 0.95) times the rate of outpatient visits. Among YAs with SCD, a longer transfer gap was associated with increased inpatient and decreased outpatient encounters in adult healthcare and more ED encounters in the first two years of adult healthcare. Strategies to reduce transfer gaps are needed.

Suppression of hepatic hepcidin expression in response to acute iron deprivation is associated with an increase of matriptase-2 protein.

Recent studies demonstrate a pivotal role for bone morphogenic protein-6 (BMP6) and matriptase-2, a protein encoded by the TMPRSS6 gene, in the induction and suppression of hepatic hepcidin expression, respectively. We examined their expression profiles in the liver and showed a predominant localization of BMP6 mRNA in nonparenchymal cells and exclusive expression of TMPRSS6 mRNA in hepatocytes. In rats fed an iron-deficient (ID) diet for 24 hours, the rapid decrease of transferrin saturation from 71% to 24% (control vs ID diet) was associated with a 100-fold decrease in hepcidin mRNA compared with the corresponding controls. These results indicated a close correlation of low transferrin saturation with decreased hepcidin mRNA. The lower phosphorylated Smad1/5/8 detected in the ID rat livers suggests that the suppressed hepcidin expression results from the inhibition of BMP signaling. Quantitative real-time reverse transcription polymerase chain reaction analysis revealed no significant change in either BMP6 or TMPRSS6 mRNA in the liver. However, an increase in matriptase-2 protein in the liver from ID rats was detected, suggesting that suppression of hepcidin expression in response to acute iron deprivation is mediated by an increase in matriptase-2 protein levels.

Multiple determinants within iron-responsive elements dictate iron regulatory protein binding and regulatory hierarchy.

Iron regulatory proteins (IRPs) are iron-regulated RNA binding proteins that, along with iron-responsive elements (IREs), control the translation of a diverse set of mRNA with 5' IRE. Dysregulation of IRP action causes disease with etiology that may reflect differential control of IRE-containing mRNA. IREs are defined by a conserved stem-loop structure including a midstem bulge at C8 and a terminal CAGUGH sequence that forms an AGU pseudo-triloop and N19 bulge. C8 and the pseudo-triloop nucleotides make the majority of the 22 identified bonds with IRP1. We show that IRP1 binds 5' IREs in a hierarchy extending over a ninefold range of affinities that encompasses changes in IRE binding affinity observed with human L-ferritin IRE mutants. The limits of this IRE binding hierarchy are predicted to arise due to small differences in binding energy (e.g., equivalent to one H-bond). We demonstrate that multiple regions of the IRE stem not predicted to contact IRP1 help establish the binding hierarchy with the sequence and structure of the C8 region displaying a major role. In contrast, base-pairing and stacking in the upper stem region proximal to the terminal loop had a minor role. Unexpectedly, an N20 bulge compensated for the lack of an N19 bulge, suggesting the existence of novel IREs. Taken together, we suggest that a regulatory binding hierarchy is established through the impact of the IRE stem on the strength, not the number, of bonds between C8 or pseudo-triloop nucleotides and IRP1 or through their impact on an induced fit mechanism of binding.

Between a Rock and a Hard Place: COVID-19 Lessons Learned From Providers Rounding at Skilled Nursing Facilities in the Rural Midwest.

On March 11, 2020, coronavirus disease 2019 (COVID-19) was classified as a pandemic, setting in motion unprecedented practice changes across the healthcare industry. Never was this more evident than in Skilled Nursing Facilities (SNFs). SNFs were tested on multiple fronts, requiring innovation and perseverance at levels never before seen. Lessons learned from this setting to better prepare for the next pandemic include: updating and standardizing infection control and prevention policies, ensuring the supply chain keeps up with demand, updating infrastructure, creating a work environment that promotes well-being, and having clear communication plans.

Assessment of transition readiness to predict health care utilization during transition to adult care in sickle cell disease.

BACKGROUND: Transition-age patients with sickle cell disease (SCD) are at risk for poor outcomes associated with incomplete transition readiness and neurocognitive deficits. Study objectives were to: 1) test if a SCD-specific measure of self-management skills was associated with transition outcomes and 2) evaluate if caregiver-reported executive functioning was associated with self-management skills and transition outcomes among youth with SCD. RESEARCH DESIGN AND METHODS: Youth/caregivers were selected from a longitudinal cohort study. Caregivers completed the Behavior Rating Inventory of Executive Function (BRIEF); caregivers and youth completed the Self-Management Skills Checklist (SMSC) at a median age of 16.8 ± 0.6 years. Non-parametric tests compared SMSC and transition outcomes. Regression assessed the incremental validity of SMSC in predicting transition outcomes. RESULTS: In total, 95 participants (54% male, 55% severe genotype) completed the SMSC assessment. Most participants (87%) transferred to adult care within six months and 87% were retained for at least 12 months. BRIEF and caregiver-reported SMSC assessments were weakly, negatively correlated (ρ = -0.25, p = 0.0392) but were not significant in predicting transition outcomes (p > 0.05). CONCLUSIONS: The SMSC and executive function did not predict adult care engagement. Development of readiness assessments that predict care engagement and reflect self-efficacy is important for monitoring transition-aged patients with SCD.

Differential translational control of 5' IRE-containing mRNA in response to dietary iron deficiency and acute iron overload.

Iron regulatory proteins (IRPs) are iron-responsive RNA binding proteins that dictate changes in cellular iron metabolism in animal cells by controlling the fate of mRNAs containing iron responsive elements (IREs). IRPs have broader physiological roles as some targeted mRNAs encode proteins with functions beyond iron metabolism suggesting hierarchical regulation of IRP-targeted mRNAs. We observe that the translational regulation of IRP-targeted mRNAs encoding iron storage (L- and H-ferritins) and export (ferroportin) proteins have different set-points of iron responsiveness compared to that for the TCA cycle enzyme mitochondrial aconitase. The ferritins and ferroportin mRNA were largely translationally repressed in the liver of rats fed a normal diet whereas mitochondrial aconitase mRNA is primarily polysome bound. Consequently, acute iron overload increases polysome association of H- and L-ferritin and ferroportin mRNAs while mitochondrial aconitase mRNA showed little stimulation. Conversely, mitochondrial aconitase mRNA is most responsive in iron deficiency. These differences in regulation were associated with a faster off-rate of IRP1 for the IRE of mitochondrial aconitase in comparison to that of L-ferritin. Thus, hierarchical control of mRNA translation by IRPs involves selective control of cellular functions acting at different states of cellular iron status and that are critical for adaptations to iron deficiency or prevention of iron toxicity.

Prostatic adenocarcinoma with novel NTRK3 gene fusion: a case report.

TMPRSS2-ERG gene fusion occurs in approximately 50% of prostatic adenocarcinoma and their expression is associated with aggressive phenotype, higher tumor stage, and tumor metastasis. A case of prostatic adenocarcinoma with IRF2BP2-NTRK1 translocation was previously reported. We report a prostatic adenocarcinoma with novel NTRK3 gene fusion that occurs in a 71-year-old male patient with aggressive histologic phenotype and multiple bony metastases. Prostatic biopsy revealed that there is a prostatic adenocarcinoma with a Gleason score of 9 (4+5), grade group 5, and multiple sites of perineural and ganglional invasion. Fluorescence in-situ hybridization (FISH) and next-generation sequencing were performed. FISH studies showed a breakage within the NTRK3 gene in prostatic adenocarcinoma cells. Next-generation sequencing confirmed that there is a PRPSAP1-NTRK3 translocation in the prostatic adenocarcinoma. In addition, ASXL1, KIF5B, MED12, PIK3CA mutations were found. NTRK alterations or dysregulation of PI3K signaling pathway were found in many types of cancers. TRK inhibitors including larotrectinib and entrectinib were approved by the US Food and Drug Administration for treating TRK fusion-positive malignant tumors and PI3K/AKT/mTOR pathway inhibitors were under clinical studies on various cancers including prostate cancer. In our current case, both NTRK3 and PIK3CA may serve as biomarkers for precision targeted therapy.

Using Qualitative Perspectives of Adolescents with Sickle Cell Disease and Caregivers to Develop Healthcare Transition Programming.

Youth with sickle cell disease (SCD) are living longer, requiring transition from pediatric to adult health care. Transition programs have been created to improve transition readiness and help patients take responsibility for their health. The aim of this study was to explore the usefulness of current transition materials and identify unmet transition needs from the perspective of adolescents with sickle cell disease (SCD) and caregivers to refine transition programming and interventions. Focus groups were conducted with 14 adolescents with SCD (Mean age = 14.6 years, SD = 1.9) and 20 caregivers (Mean age = 43.2 years, SD = 9.3) to gather perspectives about transition to adult care, current transition program materials and recommendations for future programming. Four themes emerged: (a) transition skills and knowledge needs, (b) change in health care responsibility, (c) concerns with adult SCD care, and (d) useful transition readiness strategies and resources. The findings of this study were used to develop Web based educational modules, experiential transition skills learning, and an adolescent and caregiver hematology support group. Findings highlight the need to conduct periodic readiness assessments, provide opportunities and scaffolding to learn skills based on readiness level, and help build social support networks to encourage and facilitate learning.

The IRP1-HIF-2α axis coordinates iron and oxygen sensing with erythropoiesis and iron absorption.

Red blood cell production is a finely tuned process that requires coordinated oxygen- and iron-dependent regulation of cell differentiation and iron metabolism. Here, we show that translational regulation of hypoxia-inducible factor 2α (HIF-2α) synthesis by iron regulatory protein 1 (IRP1) is critical for controlling erythrocyte number. IRP1-null (Irp1(-/-)) mice display a marked transient polycythemia. HIF-2α messenger RNA (mRNA) is derepressed in kidneys of Irp1(-/-) mice but not in kidneys of Irp2(-/-) mice, leading to increased renal erythropoietin (Epo) mRNA and inappropriately elevated serum Epo levels. Expression of the iron transport genes DCytb, Dmt1, and ferroportin, as well as other HIF-2α targets, is enhanced in Irp1(-/-) duodenum. Analysis of mRNA translation state in the liver revealed IRP1-dependent dysregulation of HIF-2α mRNA translation, whereas IRP2 deficiency derepressed translation of all other known 5' iron response element (IRE)-containing mRNAs expressed in the liver. These results uncover separable physiological roles of each IRP and identify IRP1 as a therapeutic target for manipulating HIF-2α action in hematologic, oncologic, and other disorders.

A transition pilot program for adolescents with sickle cell disease.

INTRODUCTION: Transition from pediatric to adult care is challenging for adolescents with chronic illnesses, including those with sickle cell disease (SCD). We describe a pilot program created to facilitate transition from pediatric to adult care by helping adolescents with SCD identify an adult medical home. METHODS: We investigated the feasibility of this program by evaluation of overall participation, satisfaction, and acceptance. A secondary objective was to compare the proportion of adolescents who fulfilled a first appointment with an adult hematologist among participants and nonparticipants. RESULTS: During the first 18 months of the program, 83 adolescents were invited and 34 (41%) agreed to participate; 25 (74%) completed their first visit within 3 months after leaving the pediatric program, compared with 16 of 49 (33%) of nonparticipants (p = .0002). Overall, 41 of 83 adolescents (49%) completed an appointment with an adult SCD program, regardless of program participation, in contrast with 11 of 75 adolescents (15%) who did so during the 18 months before the program was created (p < .0001). DISCUSSION: This transition pilot program was feasible, and most adolescent participants with SCD established an adult medical home.