Hematopoietic Stem Cell Transplantation in Children with Sickle Cell Disease and Thalassemia Major: A National Database Study.

In patients with sickle cell disease (SCD) and beta-thalassemia major (TM), allogeneic hematopoietic stem cell transplantation (HSCT) was considered the only curative treatment option with a good survival rate. However, with the recent approval of gene therapies, more information is needed to understand the benefits and risks of these interventions. We performed a retrospective analysis of the Kids Inpatient Database to describe demographic features, short-term complications, and hospital charges of patients with SCD and TM treated with HSCT during 2006-2019 in the United States. The database was filtered using the International Classification of Diseases, 9th and 10th edition codes to identify children under 20 years of age with SCD or TM who underwent HSCT. A total of 513 children with SCD or TM who received HSCT were analyzed. The prevalence of HSCT per 1000,000 U.S. population increased from 0.31 in 2006 to 1.99 in 2019 (p < 0.001). The median age of children with SCD who underwent HSCT was 10 (6-15) years, and that for TM was 6 (3-11.5) years (p < 0.001). The combined mortality rate was 4% (2.4%-6.6%) but higher in the TM group. The length-of-stay and total charges were higher in the TM population (p < 0.01). This study provides national data on HSCT among hospitalized children with SCD and TM in the United States, demonstrating an increasing use of HSCT between 2006 and 2019. Although hospital mortality of HSCT in these conditions is low, it still represents a challenge, especially in TM patients.

Widespread choroid plexus contamination in sampling and profiling of brain tissue.

The choroid plexus, a tissue responsible for producing cerebrospinal fluid, is found predominantly in the lateral and fourth ventricles of the brain. This highly vascularized and ciliated tissue is made up of specialized epithelial cells and capillary networks surrounded by connective tissue. Given the complex structure of the choroid plexus, this can potentially result in contamination during routine tissue dissection. Bulk and single-cell RNA sequencing studies, as well as genome-wide in situ hybridization experiments (Allen Brain Atlas), have identified several canonical markers of choroid plexus such as Ttr, Folr1, and Prlr. We used the Ttr gene as a marker to query the Gene Expression Omnibus database for transcriptome studies of brain tissue and identified at least some level of likely choroid contamination in numerous studies that could have potentially confounded data analysis and interpretation. We also analyzed transcriptomic datasets from human samples from Allen Brain Atlas and the Genotype-Tissue Expression (GTEx) database and found abundant choroid contamination, with regions in closer proximity to choroid more likely to be impacted such as hippocampus, cervical spinal cord, substantia nigra, hypothalamus, and amygdala. In addition, analysis of both the Allen Brain Atlas and GTEx datasets for differentially expressed genes between likely "high contamination" and "low contamination" groups revealed a clear enrichment of choroid plexus marker genes and gene ontology pathways characteristic of these ciliated choroid cells. Inclusion of these contaminated samples could result in biological misinterpretation or simply add to the statistical noise and mask true effects. We cannot assert that Ttr or other genes/proteins queried in targeted assays are artifacts from choroid contamination as some of these differentials may be due to true biological effects. However, for studies that have an unequal distribution of choroid contamination among groups, investigators may wish to remove contaminated samples from analyses or incorporate choroid marker gene expression into their statistical modeling. In addition, we suggest that a simple RT-qPCR or western blot for choroid markers would mitigate unintended choroid contamination for any experiment, but particularly for samples intended for more costly omic profiling. This study highlights an unexpected problem for neuroscientists, but it is also quite possible that unintended contamination of adjacent structures occurs during dissections for other tissues but has not been widely recognized.

Estrous Cycle Modulation of Feeding and Relaxin-3/Rxfp3 mRNA Expression: Implications for Estradiol Action.

INTRODUCTION: Food intake varies during the ovarian hormone/estrous cycle in humans and rodents, an effect mediated mainly by estradiol. A potential mediator of the central anorectic effects of estradiol is the neuropeptide relaxin-3 (RLN3) synthetized in the nucleus incertus (NI) and acting via the relaxin family peptide-3 receptor (RXFP3). METHODS: We investigated the relationship between RLN3/RXFP3 signaling and feeding behavior across the female rat estrous cycle. We used in situ hybridization to investigate expression patterns of Rln3 mRNA in NI and Rxfp3 mRNA in the hypothalamic paraventricular nucleus (PVN), lateral hypothalamic area (LHA), medial preoptic area (MPA), and bed nucleus of the stria terminalis (BNST), across the estrous cycle. We identified expression of estrogen receptors (ERs) in the NI using droplet digital PCR and assessed the electrophysiological responsiveness of NI neurons to estradiol in brain slices. RESULTS: Rln3 mRNA reached the lowest levels in the NI pars compacta during proestrus. Rxfp3 mRNA levels varied across the estrous cycle in a region-specific manner, with changes observed in the perifornical LHA, magnocellular PVN, dorsal BNST, and MPA, but not in the parvocellular PVN or lateral LHA. G protein-coupled estrogen receptor 1 (Gper1) mRNA was the most abundant ER transcript in the NI. Estradiol inhibited 33% of type 1 NI neurons, including RLN3-positive cells. CONCLUSION: These findings demonstrate that the RLN3/RXFP3 system is modulated by the estrous cycle, and although further studies are required to better elucidate the cellular and molecular mechanisms of estradiol signaling, current results implicate the involvement of the RLN3/RXFP3 system in food intake fluctuations observed across the estrous cycle in female rats.

Differential effects of relaxin-3 and a selective relaxin-3 receptor agonist on food and water intake and hypothalamic neuronal activity in rats.

The neuropeptide relaxin-3 (RLN3) binds with high affinity to its cognate receptor, relaxin-family peptide receptor 3 (RXFP3), and with lower affinity to RXFP1, the cognate receptor for relaxin. Intracerebroventricular (icv) administration of RLN3 in rats strongly increases food and water intake and alters the activity of the hypothalamic-pituitary-adrenal (HPA) and gonadal (HPG) axes, but the relative involvement of RXFP3 and RXFP1 in these effects is not known. Therefore, the effects of icv administration of equimolar (1.1 nmol) amounts of RLN3 and the RXFP3-selective agonist RXFP3-A2 on food and water intake, plasma levels of corticosterone, testosterone, and oxytocin and c-fos mRNA expression in key hypothalamic regions in male rats were compared. Food intake was increased by both RLN3 and RXFP3-A2, but the orexigenic effects of RXFP3-A2 were significantly stronger than RLN3, 30 and 60min after injection. Water intake and plasma corticosterone and testosterone levels were significantly increased by RLN3, but not by RXFP3-A2. Conversely, RXFP3-A2 but not RLN3 decreased oxytocin plasma levels. RLN3, but not RXFP3-A2, increased c-fos mRNA levels in the parvocellular (PVNp) and magnocellular (PVNm) paraventricular and supraoptic (SON) hypothalamic nuclei, in the ventral medial preoptic area (MPAv), and in the organum vasculosum of the lamina terminalis (OVLT). A significant increase in c-fos mRNA expression was induced in the perifornical lateral hypothalamic area (LHApf) by RLN3 and RXFP3-A2. These results suggest that RXFP1 is involved in the RLN3 stimulation of water intake and activation of the HPA and HPG axes. The reduced food intake stimulation by RLN3 compared to RXFP3-A2 may relate to activation of both orexigenic and anorexigenic circuits by RLN3.