Rapid, sensitive detection of bacteria in platelet samples with Fountain Flow Cytometry.

BACKGROUND: There is a current need to develop a technique for bacterial screening of platelet donations that is more rapid, sensitive, and economical than alternatives. The objective of this research was to perform a pilot test of the viability of Fountain Flow Cytometry (FFC), for the rapid and sensitive detection of bacteria in platelet donations. METHODS: Platelet samples were inoculated with serial dilutions of five selected bacterial strains. Samples were then centrifuged, reconstituted in buffer, and stained with a live/dead bacterial stain cocktail. The resulting aqueous sample was measured by FFC, in which the sample passed as a stream in front of an LED, which excited the fluorescent labels. Fluorescence was detected with a digital camera as the sample flowed toward it. RESULTS: Fountain Flow Cytometry enumeration yielded results that were linear with bacterial concentration, having an R2 of ≥0.98 with a detection efficiency of 92%±3%. Measurements of uninoculated samples showed a false-positive detection rate at ~400 colony forming units (CFU)/mL. Detection of bacterial concentrations in platelets above this threshold can be made in ~15 minutes, including sample preparation time. CONCLUSION: This pilot study supports the efficacy of FFC for the rapid and sensitive screening of platelet donations for bacteria.

Heterozygous Eif4nif1 Stop Gain Mice Replicate the Primary Ovarian Insufficiency Phenotype in Women.

We created the c.1286C>G stop-gain mutation found in a family with primary ovarian insufficiency (POI) at age 30 years. The Eif4enif1 C57/Bl6 transgenic mouse model contained a floxed exon 10-19 cassette with a conditional knock-in cassette containing the c.1286C>G stop-gain mutation in exon 10. The hybrid offspring of CMV- Cre mice with Eif4enif1 WT/flx mice were designated Eif4enif1 WT/ Δ for simplicity. A subset of female heterozygotes ( Eif4enif1 WT/ Δ ) had no litters. In those with litters, the final litter was earlier (5.4±2.6 vs. 10.5±0.7 months; p=0.02). Heterozygous breeding pair ( Eif4enif1 WT/ Δ x Eif4enif1 WT/ Δ ) litter size was 60% of WT litter size (3.9±2.0 vs. 6.5±3.0 pups/litter; p <0.001). The genotypes were 35% Eif4enif1 WT/flx and 65% Eif4enif1 WT/ Δ , with no homozygotes. Homozygote embryos did not develop beyond the 4-8 cell stage. The number of follicles in ovaries from Eif4enif1 WT/ Δ mice was lower starting at the primordial (499±290 vs. 1445±381) and primary follicle stage (1069±346 vs. 1450±193) on day 10 (p<0.05). The preantral follicle number was lower starting on day 21 (213±86 vs. 522±227; p<0.01). Examination of ribosome protected mRNAs (RPR) demonstrated altered mRNA expression. The Eif4enif1 stop-gain mice replicate the POI phenotype in women. The unique mouse model provides a platform to study regulation of protein translation across oocyte and embryo development in mammals.

Impact of Maternal Exercise on Mice Offspring Development, Pulmonary Hypertension, and Vascular Remodeling in Chronic Hypoxia.

PURPOSE: Chronic, high-altitude hypoxic exposure increases the risk of high-altitude pulmonary hypertension (PH). Emerging evidence shows maternal exercise may improve offspring resistance to disease throughout life. The purpose of this study is to determine if maternal exercise mitigates chronic hypoxic-induced changes in the offspring indicative of high-altitude pulmonary hypertension development. METHODS: Female adult C57BL/6 J mice were randomly allocated to nonexercise or exercise conditions. Exercise consisted of voluntary running wheel exercise for four weeks during the perinatal period. Three days after birth, the pups remained at low altitude (normoxia) or were exposed to hypobaric hypoxia of 450 mmHg to simulate ~4500 m altitude exposure until 8 weeks of age. The study consisted of 4 groups: Hypoxia + Nonexercise pregnancy, Hypoxia + Exercise, or the respective, normoxia conditions (Normoxia + Nonexercise or Normoxia + Exercise). Offspring body size, motor function, right ventricular systolic pressure (RVSP), and cardiopulmonary morphology were assessed after 8 weeks in normoxia or hypoxia. RESULTS: Both hypoxic groups had smaller body sizes, reduced motor function, increased hematocrit, RVSP, muscularization in medium-sized pulmonary arteries, as well as right ventricular hypertrophy and contractility compared to the normoxic groups ( p < 0.05). CONCLUSIONS: Chronic hypoxia simulating 4500 m attenuated growth, lowered motor function, and elicited PH development. Voluntary maternal exercise did not significantly decrease RVSP in the offspring, which aligned with a lack of effect to attenuate abnormal body size and cardiopulmonary development due to chronic hypoxia. These findings are preliminary in nature and more powered studies through larger group sizes are required to generalize the results to the population.

Chronic hypoxia disrupts T regulatory cell phenotype contributing to the emergence of exTreg-TH17 cells.

The imbalance between pro-inflammatory T helper 17 (TH17) cells and anti-inflammatory regulatory T cells (Tregs) has been implicated in multiple inflammatory and autoimmune conditions, but the effects of chronic hypoxia (CH) on this balance have yet to be explored. CH-exposed mice have an increased prevalence of TH17 cells in the lungs with no change in Tregs. This imbalance is significant because it precedes the development of pulmonary hypertension (PH), and TH17 cells are a major contributor to CH-induced PH. While Tregs have been shown to attenuate or prevent the development of certain types of PH through activation and adoptive transfer experiments, why Tregs remain unable to prevent disease progression naturally, specifically in CH-induced PH, remains unclear. Our study aimed to test the hypothesis that increased TH17 cells observed following CH are caused by decreased circulating levels of Tregs and switching of Tregs to exTreg-TH17 cells, following CH. We compared gene expression profiles of Tregs from normoxia or 5-day CH splenocytes harvested from Foxp3tm9(EGFP/cre/ERT2)Ayr/J x Ai14-tdTomato mice, which allowed for Treg lineage tracing through the presence or absence of EGFP and/or tdTomato expression. We found Tregs in CH exposed mice contained gene profiles consistent with decreased suppressive ability. We determined cell prevalence and expression of CD25 and OX40, proteins critical for Treg function, in splenocytes from Foxp3tm9(EGFP/cre/ERT2)Ayr/J x Ai14-tdTomato mice under the same conditions. We found TH17 cells to be increased and Tregs to be decreased, following CH, with protein expression of CD25 and OX40 in Tregs matching the gene expression data. Finally, using the lineage tracing ability of this mouse model, we were able to demonstrate the emergence of exTreg-TH17 cells, following CH. These findings suggest that CH causes a decrease in Treg suppressive capacity, and exTregs respond to CH by transitioning to TH17 cells, both of which tilt the Treg-TH17 cell balance toward TH17 cells, creating a pro-inflammatory environment.

Causal and Candidate Gene Variants in a Large Cohort of Women With Primary Ovarian Insufficiency.

CONTEXT: A genetic etiology likely accounts for the majority of unexplained primary ovarian insufficiency (POI). OBJECTIVE: We hypothesized that heterozygous rare variants and variants in enhanced categories are associated with POI. DESIGN: The study was an observational study. SETTING: Subjects were recruited at academic institutions. PATIENTS: Subjects from Boston (n = 98), the National Institutes of Health and Washington University (n = 98), Pittsburgh (n = 20), Italy (n = 43), and France (n = 32) were diagnosed with POI (amenorrhea with an elevated follicle-stimulating hormone level). Controls were recruited for health in old age or were from the 1000 Genomes Project (total n = 233). INTERVENTION: We performed whole exome sequencing (WES), and data were analyzed using a rare variant scoring method and a Bayes factor-based framework for identifying genes harboring pathogenic variants. We performed functional studies on identified genes that were not previously implicated in POI in a D. melanogaster model. MAIN OUTCOME: Genes with rare pathogenic variants and gene sets with increased burden of deleterious variants were identified. RESULTS: Candidate heterozygous variants were identified in known genes and genes with functional evidence. Gene sets with increased burden of deleterious alleles included the categories transcription and translation, DNA damage and repair, meiosis and cell division. Variants were found in novel genes from the enhanced categories. Functional evidence supported 7 new risk genes for POI (USP36, VCP, WDR33, PIWIL3, NPM2, LLGL1, and BOD1L1). CONCLUSIONS: Candidate causative variants were identified through WES in women with POI. Aggregating clinical data and genetic risk with a categorical approach may expand the genetic architecture of heterozygous rare gene variants causing risk for POI.

PRL Mutation Causing Alactogenesis: Insights Into Prolactin Structure and Function Relationships.

CONTEXT: Isolated prolactin deficiency is a rare disorder manifesting as absence of puerperal lactation. We identified a 2-generation family with 3 women experiencing alactogenesis. OBJECTIVE: We hypothesized a heterozygous genetic mutation. METHODS: This was a family-based study. Two generations of women (proband, sister, and niece) with puerperal alactogenesis and one control were studied. Prolactin levels in the 3 women ranged from 0.618 to 1.4 ng/mL (range, 2.8-29.2 ng/mL). All the women had regular menstrual cycles during their reproductive years. The niece required fertility treatment to become pregnant and the proband and sister underwent menopause before age 45 years. Prolactin gene (PRL) exons 1 to 5 were sequenced. We sought a heterozygous, deleterious gene variant with functional consequences. RESULTS: We identified a heterozygous mutation (c.658C > T) changing CGA to TGA (p.Arg220Ter) in exon 5 of the prolactin gene. Transfection of PRL containing the stop gain mutation resulted in similar intracellular prolactin levels compared to PRL wild type, but little detectable immunoactive or bioactive prolactin in conditioned medium. Prolactin secretion was also impaired by a PRL stop gain mutation deleting both of the terminal cysteine amino acids (c.652A > T; p.Lys218Ter). CONCLUSION: This is the first report of a PRL mutation causing familial prolactin deficiency and alactogenesis. The loss of the terminal cysteine resulted in failure of prolactin secretion. Secretion was not rescued by deleting the penultimate cysteine, with which it forms a disulfide bond. These data suggest that the PRL C terminal is critical for protein secretion.

Single nucleus multi-omics regulatory landscape of the murine pituitary.

To provide a multi-omics resource and investigate transcriptional regulatory mechanisms, we profile the transcriptome, chromatin accessibility, and methylation status of over 70,000 single nuclei (sn) from adult mouse pituitaries. Paired snRNAseq and snATACseq datasets from individual animals highlight a continuum between developmental epigenetically-encoded cell types and transcriptionally-determined transient cell states. Co-accessibility analysis-based identification of a putative Fshb cis-regulatory domain that overlaps the fertility-linked rs11031006 human polymorphism, followed by experimental validation illustrate the use of this resource for hypothesis generation. We also identify transcriptional and chromatin accessibility programs distinguishing each major cell type. Regulons, which are co-regulated gene sets sharing binding sites for a common transcription factor driver, recapitulate cell type clustering. We identify both cell type-specific and sex-specific regulons that are highly correlated with promoter accessibility, but not with methylation state, supporting the centrality of chromatin accessibility in shaping cell-defining transcriptional programs. The sn multi-omics atlas is accessible at snpituitaryatlas.princeton.edu.

Primary Ovarian Insufficiency and Azoospermia in Carriers of a Homozygous PSMC3IP Stop Gain Mutation.

Context: The etiology of primary ovarian insufficiency (POI) remains unknown in most cases. Objective: We sought to identify the genes causing POI. Design: The study was a familial genetic study. Setting: The study was performed at two academic institutions. Patients: We identified a consanguineous Yemeni family in which four daughters had POI. A brother had azoospermia. Intervention: DNA was subjected to whole genome sequencing. Shared regions of homozygosity were identified using Truploidy and prioritized using the Variant Annotation, Analysis, and Search Tool with control data from 387 healthy subjects. Imaging and quantification of protein localization and mitochondrial function were examined in cell lines. Main Outcome: Homozygous recessive gene variants shared by the four sisters. Results: The sisters shared a homozygous stop gain mutation in exon 6 of PSMC3IP (c.489 C>G, p.Tyr163Ter) and a missense variant in exon 1 of CLPP (c.100C>T, p.Pro34Ser). The affected brother also carried the homozygous PSMC3IP mutation. Functional studies demonstrated mitochondrial fragmentation in cells infected with the CLPP mutation. However, no abnormality was found in mitochondrial targeting or respiration. Conclusions: The PSMC3IP mutation provides additional evidence that mutations in meiotic homologous recombination and DNA repair genes result in distinct female and male reproductive phenotypes, including delayed puberty and primary amenorrhea caused by POI (XX gonadal dysgenesis) in females but isolated azoospermia with normal pubertal development in males. The findings also suggest that the N-terminal missense mutation in CLPP does not cause substantial mitochondrial dysfunction or contribute to ovarian insufficiency in an oligogenic manner.

POLR2C Mutations Are Associated With Primary Ovarian Insufficiency in Women.

CONTEXT: Primary ovarian insufficiency (POI) results from a premature loss of oocytes, causing infertility and early menopause. The etiology of POI remains unknown in a majority of cases. OBJECTIVE: To identify candidate genes in families affected by POI. DESIGN: This was a family-based genetic study. SETTING: The study was performed at two academic institutions. PATIENTS AND OTHER PARTICIPANTS: A family with four generations of women affected by POI (n = 5). Four of these women, three with an associated autoimmune diagnosis, were studied. The controls (n = 387) were recruited for health in old age. INTERVENTION: Whole-genome sequencing was performed. MAIN OUTCOME MEASURE: Candidate genes were identified by comparing gene mutations in three family members and 387 control subjects analyzed simultaneously using the pedigree Variant Annotation, Analysis and Search Tool. Data were also compared with that in publicly available databases. RESULTS: We identified a heterozygous nonsense mutation in a subunit of RNA polymerase II (POLR2C) that synthesizes messenger RNA. A rare sequence variant in POLR2C was also identified in one of 96 women with sporadic POI. POLR2C expression was decreased in the proband compared with women with POI from another cause. Knockdown in an embryonic carcinoma cell line resulted in decreased protein production and impaired cell proliferation. CONCLUSIONS: These data support a role for RNA polymerase II mutations as candidates in the etiology of POI. The current data also support results from genome-wide association studies that hypothesize a role for RNA polymerase II subunits in age at menopause in the population.