Identifying metabolite markers for preterm birth in cervicovaginal fluid by magnetic resonance spectroscopy

Introduction Preterm birth (PTB) may be preceded by changes in the vaginal microflora and metabolite profiles. Objectives We sought to characterise the metabolite profile of cervicovaginal fluid (CVF) of pregnant women by 1H NMR spectroscopy, and assess their predictive value for PTB. Methods A pair of high-vaginal swabs was obtained from pregnant women with no evidence of clinical infection and grouped as follows: asymptomatic low risk (ALR) women with no previous history of PTB, assessed at 20–22 gestational weeks, g.w., n = 83; asymptomatic high risk (AHR) women with a previous history of PTB, assessed at both 20–22 g.w., n = 71, and 26–28 g.w., n = 58; and women presenting with symptoms of preterm labor (PTL) (SYM), assessed at 24–36 g.w., n = 65. Vaginal secretions were dissolved in phosphate buffered saline and scanned with a 9.4 T NMR spectrometer. Results Six metabolites (lactate, alanine, acetate, glutamine/glutamate, succinate and glucose) were analysed. In all study cohorts vaginal pH correlated with lactate integral (r = -0.62, p\0.0001). Lactate integrals were higher in the term ALR compared to the AHR (20–22 g.w.) women (p = 0.003). Acetate integrals were higher in the preterm versus term women for the AHR (20–22 g.w.) (p = 0.048) and SYM (p = 0.003) groups; and was predictive of PTB\37 g.w. (AUC 0.78; 95 % CI 0.61–0.95), and delivery within 2 weeks of the index assessment (AUC 0.84; 95 % CI 0.64–1) in the SYM women, whilst other metabolites were not. Conclusion High CVF acetate integral of women with symptoms of PTL appears predictive of preterm delivery, as well as delivery within 2 weeks of presentation

Bone progenitor dysfunction induces myelodysplasia and secondary leukaemia

Mesenchymal cell populations contribute to microenvironments regulating stem cells and the growth of malignant cells. Osteolineage cells participate in the hematopoietic stem cell niche. Here, we report that deletion of the miRNA processing endonuclease Dicer1 selectively in mesenchymal osteoprogenitors induces markedly disordered hematopoiesis. Hematopoietic changes affected multiple lineages recapitulating key features of human myelodysplastic syndrome (MDS) including the development of acute myelogenous leukemia. These changes were microenvironment dependent and induced by specific cells in the osteolineage. Dicer1−/− osteoprogenitors expressed reduced levels of Sbds, the gene mutated in the human bone marrow failure and leukemia predisposition Shwachman-Bodian-Diamond Syndrome. Deletion of Sbds in osteoprogenitors largely phenocopied Dicer1 deletion. These data demonstrate that differentiation stage-specific perturbations in osteolineage cells can induce complex hematological disorders and indicate the central role individual cellular elements of ‘estroma’ can play in tissue homeostasis. They reveal that primary changes in the hematopoietic microenvironment can initiate secondary neoplastic disease

Niche Induced Myelodysplasia and Secondary Hematopoietic Neoplasia Caused by Deletion of Dicer1 in Osteoprogenitor Cells.

Abstract Abstract 247 Introduction: Mesenchymal cells are a part of virtually every tissue in metazoans and are thought to participate in organ formation and homeostasis. In the hematopoietic system, mesenchymal cells of the osteoblast lineage have revealed their role as regulators of normal stem cell and hematopoietic physiology. Whether these cells, which have been relegated a relatively non-descript role of ‘stroma', participate in processes that result in disease is relatively understudied. Methods: To explore this, we conditionally deleted Dicer1, the endonuclease essential for miRNA biogenesis, from osteoprogenitor cells by intercrossing transgenic mice expressing a GFP-Cre recombinase under the transcriptional control of the osteoblastic lineage specific osterix promoter to mice containing conditional (floxed) Dicer1 alleles. Results: Deletion of Dicer1 from osteoprogenitor cells resulted in markedly disordered hematopoiesis, affecting multiple lineages and recapitulating key features of human myelodysplastic syndrome (MDS). These features included ineffective hematopoiesis with cytopenia, multilineage dysplasia, increased proliferation and intramedullary apoptosis of primitive hematopoietic cells, decreased B-cell progenitors, increased bone marrow vascularity and the propensity to develop hematopoietic neoplasms (myeloid sarcoma and acute monocytic leukemia-like disease). Comparative genomic hybridization of tumor and germline tissues revealed multiple genetic aberrancies in myeloid sarcomas induced by the Dicer1 deleted environment. The hematopoietic abnormalities were entirely microenvironment dependent with intact Dicer1 in hematopoietic cells. Transplantation of wild-type hematopoietic cells into the mutant environment recapitulated these abnormalities whereas, conversely, transplantation of hematopoietic cells from mutant mice into a wild-type environment resulted in complete normalization of hematopoiesis. In addition, hematopoietic abnormalities were not observed when Dicer1 was deleted from mature osteoblasts indicating a central role of osteoprogenitor cells in the regulation of hematopoiesis. Finally, gene expression profiling and cytokine arrays from osteoprogenitor cells identified candidate molecular effectors of the observed hematopoietic abnormalities. Conclusions: The data demonstrate that a distinctive, differentiation stage specific, stromal subset of osteolineage cells can induce a highly dysfunctional hematopoietic system, recapitulating key characteristics of human myelodysplastic syndrome. Further, they reveal that primary changes in a tissue microenvironment can initiate neoplastic disease. Disclosures: Scadden: Fate Therapeutics: Consultancy. </jats:sec