Autonomic Nervous System Regulation of Hematopoiesis

This thesis provides findings that add to the body of work highlighting the importance of nervous system regulation of hematopoiesis and consequently cardiovascular disease progression. Furthermore, we present a novel role for the cholinergic system, in particular in regulating blood stem cell retention in the bone marrow via altering the vessel structures in the marrow microenvironment. These findings will potentially aid in the development of treatments targeted at modulating the nervous system in the setting of cardiovascular disease

Intravenous Iron Therapy to Treat Anemia in Oncology: A Mapping Review of Randomized Controlled Trials

Anemia is a common problem when patients present with cancer, and it can worsen during treatment. Anemia can directly impact the cognitive and physical quality of life and may impair fitness for oncological therapy. The most common cause of anemia is iron deficiency. Newer intravenous (IV) iron formulations offer a safe and rapidly effective treatment option. We performed a systematic mapping review of randomized controlled trials (RCTs) evaluating intravenous iron therapy in patients with cancer and anemia and their outcomes. A total of 23 RCTs were identified. The median number of patients enrolled was 104 (IQR: 60–134). A total of 5 were focused on surgical outcomes (4 preoperative, 1 postoperative), and 15 were in adjuvant therapies for a variety of tumor types (breast, colorectal, lung, gynecological, myeloid, and lymphomas), 10 of which were in combination with erythropoietin-stimulating agents (ESAs) therapy, 2 in radiotherapy, and 1 in palliative care. Overall, the studies reported that the use of IV iron increased hemoglobin concentration and decreased transfusion rates during different cancer treatment regimes. IV iron can be administered safely throughout the cancer treatment pathway from primary surgery to the palliative setting. More studies are needed to demonstrate net clinical outcomes

High-density lipoprotein inhibits human M1 macrophage polarization through redistribution of caveolin-1

Background and PurposeMonocyte-derived macrophages are critical in the development of atherosclerosis and can adopt a wide range of functional phenotypes depending on their surrounding milieu. High-density lipoproteins (HDLs) have many cardio-protective properties including potent anti-inflammatory effects. We investigated the effects of HDL on human macrophage phenotype and the mechanisms by which these occur

Leptin-deficient obesity prolongs survival in a murine model of myelodysplastic syndrome

Obesity enhances the risk of developing myelodysplastic syndromes. However, the effect of obesity on survival is unclear. Obese people present with monocytosis due to inflammatory signals emanating from obese adipose tissue. We hypothesized that obesity-induced myelopoiesis would promote the transition of myelodysplastic syndrome to acute myeloid leukemia and accelerate mortality in obesity. Obese Ob/Ob mice or their lean littermate controls received a bone marrow transplant from NUP98-HOXD13 transgenic mice, a model of myelodysplastic syndrome. The metabolic parameters of the mice were examined throughout the course of the study, as were blood leukocytes. Myeloid cells were analyzed in the bone, spleen, liver and adipose tissue by flow cytometry halfway through the disease progression and at the endpoint. Survival curves were also calculated. Contrary to our hypothesis, transplantation of NUP98-HOXD13 bone marrow into obese recipient mice significantly increased survival time compared with lean recipient controls. While monocyte skewing was exacerbated in obese mice receiving NUP98-HOXD13 bone marrow, transformation to acute myeloid leukemia was not enhanced. Increased survival of obese mice was associated with a preservation of fat mass as well as increased myeloid cell deposition within the adipose tissue, and a concomitant reduction in detrimental myeloid cell accumulation within other organs. The study herein revealed that obesity increases survival in animals with myelodysplastic syndrome. This may be due to the greater fat mass of Ob/Ob mice, which acts as a sink for myeloid cells, preventing their accumulation in other key organs, such as the liver

Neutrophil-derived S100A8/A9 amplify granulopoiesis following myocardial infarction

Myocardial infarction (MI) triggers myelopoiesis resulting in heightened production of neutrophils. However, the mechanisms that sustain their production and recruitment to the injured heart are unclear. Using a mouse model of the permanent ligation of the left anterior descending (LAD) artery and flow cytometry, we first characterized the temporal and spatial effects of MI on different myeloid cell types. We next performed global transcriptome analysis of different cardiac cell types within the infarct to identify the drivers of acute inflammatory response and the underlying signaling pathways. Utilizing a combination of genetic and pharmacological strategies, we identified the sequalae of events that led to MI-induced myelopoiesis. Cardiac function was assessed by echocardiography. The association of early indices of neutrophilia with major adverse cardiovascular events (MACE) was studied in a cohort of acute MI patients. Induction of MI resulted in a rapid recruitment of neutrophils to the infarct, where they release specific alarmins, S100A8 and S100A9. These alarmins bind to the Toll Like Receptor (TLR) 4 and prime the Nod Like Receptor (NLR) family Pyrin Domain-Containing 3 (Nlrp3) inflammasome in naïve neutrophils and promote interleukin 1 (IL-1β) secretion. The released IL-1β interact with its receptor (Interleukin 1 Receptor Type 1, IL1R1) on hematopoietic stem and progenitor cells in the bone marrow (BM), and stimulate granulopoiesis in a cell-autonomous manner. Genetic or pharmacological strategies aimed at disruption of S100A8/A9 and its downstream signaling cascade suppress MI-induced granulopoiesis and improve cardiac function. Furthermore, in patients with acute coronary syndrome (ACS), higher neutrophil count on admission and post-revascularization correlates positively with major adverse cardiovascular disease (CVD) outcomes. Our study provides novel evidence for the primary role of neutrophil-derived alarmins (S100A8/A9) in dictating the nature of the ensuing inflammatory response following myocardial injury. Therapeutic strategies aimed at disruption of S100A8/A9 signaling or its downstream mediators (e.g. Nlrp3, IL-1β) in neutrophils suppress granulopoiesis and may improve cardiac function in ACS patients