Osteoclasts Are Important for Bone Angiogenesis

Osteoclastogenesis and angiogenesis are correlated in bone during physiological and pathological processes including development, fracture healing, bone metastases and inflammatory bone disease. However, it is unclear if and how these processes are linked. This dissertation investigates a possible causative role for osteoclasts in bone angiogenesis. First, changes in osteoclast formation and activity affected angiogenesis in a parallel fashion. Osteoclast inhibition decreased angiogenesis, while osteoclast stimulation increased angiogenesis in fetal mouse metatarsal explants. Likewise, osteoclast stimulation also increased angiogenesis in mouse calvaria in vivo, thus showing that osteoclasts and angiogenesis are linked. Further studies were conducted to determine the mechanism by which osteoclasts may increase angiogenesis. Angiogenic factor expression by osteoclasts was analyzed by reverse-trancriptase PCR and Q-PCR angiogenesis arrays of human bone marrow osteoclasts. MMP-9 was the most highly expressed osteoclast angiogenic factor at the mRNA level. Because MMP-9 is important for osteoclast and blood vessel invasion of the growth plate and fracture calluses, the role of MMP-9 in osteoclast stimulated angiogenesis was studied in depth. Osteoclast stimulation with RANKL or PTHrP failed to stimulate angiogenesis in MMP-9-/- mouse calvaria or metatarsal explants. Surprisingly, osteoclast stimulation was dramatically blunted in MMP-9-/- calvaria or metatarsal explants. However, the number of vessels per osteoclast was not different between WT and MMP-9-/- mice, indicating that osteoclasts lacking MMP-9 do not have an intrinsic angiogenic defect. Further, bone marrow cultures from WT and MMP-9-/- mice formed similar numbers of osteoclasts, demonstrating that osteoclast differentiation or precursor number is not responsible for the inability of PTHrP or RANKL to increase osteoclastogenesis in MMP-9-/- mice. These results suggest that MMP-9 is important for osteoclast-stimulated angiogenesis by affecting the number of osteoclasts at the angiogenic site due to its previously reported effects on osteoclast migration. These studies greatly increase our understanding of angiogenesis in bone and suggest an important role for osteoclasts in angiogenesis during bone development, fracture healing, bone metastasis, inflammatory bone diseases and the potential effects of osteoclast inhibitory agents on angiogenesis

Biochemical Changes in the Niche Following Tumor Cell Invasion

Metastatic cancer is the leading cause of all cancer related deaths. Prostate cancer (PCa) metastasizes preferentially to the bone marrow, specifically within the endosteal niche. Endosteal cells secrete homing molecules that may recruit PCa cells to the bone marrow. Once there, the biochemical signature of this niche regulates PCa fate including cellular dormancy or cell cycle arrest, reactivation and resistance to chemotherapeutics. Growth factors, interleukins, adhesion molecules, as well as extra‐cellular matrix proteins can collectively change the phenotype of PCa cells. Understanding the biochemical signature of endosteal niche parasitism by PCa is imperative for the establishment of new and innovative therapeutic strategies. This review seeks to summarize these important niche signatures and the potential therapeutic approaches to target metastatic PCa within the bone marrow hematopoietic stem cell (HSC) niche. J. Cell. Biochem. 118: 1956–1964, 2017. © 2016 Wiley Periodicals, Inc.Molecular interactions of PCa cells in the bone marrow microenvironment.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137340/1/jcb25843_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137340/2/jcb25843.pd

The role of emotions and physiological arousal in modulating impulsive behaviour.

Impulsivity received considerable attention in the context of drug misuse and certain neuropsychiatric conditions. Because of its great health and well-being importance, it is crucial to understand factors which modulate impulsive behaviour. As a growing body of literature indicates the role of emotional and physiological states in guiding our actions and decisions, we argue that current affective state and physiological arousal exert a significant influence on behavioural impulsivity. As 'impulsivity' is a heterogeneous concept, in this paper, we review key theories of the topic and summarise information about distinct impulsivity subtypes and their methods of assessment, pointing out to the differences between the various components of the construct. Moreover, we review existing literature on the relationship between emotional states, arousal and impulsive behaviour and suggest directions for future research

Anger and aggression in borderline personality disorder and attention deficithyperactivity disorder – does stress matter?

BACKGROUND: The impact of stress on anger and aggression in Borderline Personality Disorder (BPD) and Attention Deficit Hyperactivity Disorder (ADHD) has not been thoroughly investigated. The goal of this study was to investigate different aspects of anger and aggression in patients with these disorders. METHODS: Twenty-nine unmedicated female BPD patients, 28 ADHD patients and 30 healthy controls (HC) completed self-reports measuring trait anger, aggression and emotion regulation capacities. A modified version of the Point Subtraction Aggression Paradigm and a state anger measurement were applied under resting and stress conditions. Stress was induced by the Mannheim Multicomponent Stress Test (MMST). RESULTS: Both patient groups scored significantly higher on all self-report measures compared to HCs. Compared to ADHD patients, BPD patients reported higher trait aggression and hostility, a stronger tendency to express anger when provoked and to direct anger inwardly. Furthermore, BPD patients exhibited higher state anger than HCs and ADHD patients under both conditions and showed a stress-dependent anger increase. At the behavioral level, no significant effects were found. In BPD patients, aggression and anger were positively correlated with emotion regulation deficits. CONCLUSIONS: Our findings suggest a significant impact of stress on self-perceived state anger in BPD patients but not on aggressive behavior towards others in females with BPD or ADHD. However, it appears to be pronounced inwardly directed anger which is of clinical importance in BPD patients. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40479-017-0057-5) contains supplementary material, which is available to authorized users

Design of a Mechanical Impacter for Testing Cable Wave Propagation

ME450 Capstone Design and Manufacturing Experience: Fall 2007The United States Navy wants to know the tension in oceanographic cables submerged to depths of up to 10,000 ft. Professor Noel Perkins, with the University of Michigan, has devised a method to estimate cable tension by measuring the speed at which impact-induced waves propagate through a cable. Our objective is to work with our sponsors to design and construct a mechanical impacter prototype to use with the new testing method. Additionally, the impacter must interface with a submersible robot arm. Our design will be tested on an existing cable test bed on the University of Michigan campus.Prof. Noel Perkins, ME and US Navyhttp://deepblue.lib.umich.edu/bitstream/2027.42/57943/1/me450f07project13_report.pd

Growth Arrest‐Specific 6 (GAS6) Promotes Prostate Cancer Survival by G1 Arrest/S Phase Delay and Inhibition of Apoptosis During Chemotherapy in Bone Marrow

Prostate cancer (PCa) is known to develop resistance to chemotherapy. Growth arrest‐specific 6 (GAS6), plays a role in tumor progression by regulating growth in many cancers. Here, we explored how GAS6 regulates the cell cycle and apoptosis of PCa cells in response to chemotherapy. We found that GAS6 is sufficient to significantly increase the fraction of cells in G1 and the duration of phase in PCa cells. Importantly, the effect of GAS6 on G1 is potentiated during docetaxel chemotherapy. GAS6 altered the levels of several key cell cycle regulators, including the downregulation of Cyclin B1 (G2/M phase), CDC25A, Cyclin E1, and CDK2 (S phase entry), while the upregulation of cell cycle inhibitors p27 and p21, Cyclin D1, and CDK4. Importantly, these changes became further accentuated during docetaxel treatment in the presence of GAS6. Moreover, GAS6 alters the apoptotic response of PCa cells during docetaxel chemotherapy. Docetaxel induced PCa cell apoptosis is efficiently suppressed in PCa cell culture in the presence of GAS6 or GAS6 secreted from co‐cultured osteoblasts. Similarly, the GAS6‐expressing bone environment protects PCa cells from apoptosis within primary tumors in vivo studies. Docetaxel induced significant levels of Caspase‐3 and PARP cleavage in PCa cells, while GAS6 protected PCa cells from docetaxel‐induced apoptotic signaling. Together, these data suggest that GAS6, expressed by osteoblasts in the bone marrow, plays a significant role in the regulation of PCa cell survival during chemotherapy, which will have important implications for targeting metastatic disease. J. Cell. Biochem. 117: 2815–2824, 2016. © 2016 Wiley Periodicals, Inc.We explored how GAS6, expressed by osteoblasts, regulates the cell cycle and apoptosis in PCa cells during chemotherapy in the bone marrow. We demonstrate that GAS6 significantly increases the number of G1 arrested cells by altering signaling networks associated with G1 arrest and S phase delay. Our results suggest that GAS6 contributes to the regulation of PCa cell survival during chemotherapy in the bone marrow microenvironment.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134410/1/jcb25582_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134410/2/jcb25582.pd

Mer Tyrosine Kinase Regulates Disseminated Prostate Cancer Cellular Dormancy

Many prostate cancer (PCa) recurrences are thought to be due to reactivation of disseminated tumor cells (DTCs). We previously found a role of the TAM family of receptor tyrosine kinases TYRO3, AXL, and MERTK in PCa dormancy regulation. However, the mechanism and contributions of the individual TAM receptors is largely unknown. Knockdown of MERTK, but not AXL or TYRO3 by shRNA in PCa cells induced a decreased ratio of Pâ Erk1/2 to Pâ p38, increased expression of p27, NR2F1, SOX2, and NANOG, induced higher levels of histone H3K9me3 and H3K27me3, and induced a G1/G0 arrest, all of which are associated with dormancy. Similar effects were also observed with siRNA. Most importantly, knockdown of MERTK in PCa cells increased metastasis free survival in an intraâ cardiac injection mouse xenograft model. MERTK knockdown also failed to inhibit PCa growth in vitro and subcutaneous growth in vivo, which suggests that MERTK has specificity for dormancy regulation or requires a signal from the PCa microenvironment. The effects of MERTK on the cell cycle and histone methylation were reversed by p38 inhibitor SB203580, which indicates the importance of MAP kinases for MERTK dormancy regulation. Overall, this study shows that MERTK stimulates PCa dormancy escape through a MAP kinase dependent mechanism, also involving p27, pluripotency transcription factors, and histone methylation. J. Cell. Biochem. 118: 891â 902, 2017. © 2016 Wiley Periodicals, Inc.Escape from cellular dormancy is the process where previously dormant single disseminated tumor cells reactivate to form cancer microâ metastases, which continue to grow and ultimately make the disease incurable. Here, were show that Mer tyrosine kinase is important for prostate cancer dormancy escape through a mechanism involving MAP kinases, cell cycle inhibitors, epigenetics, and transcription factors associated with pluripotent cells.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136285/1/jcb25768_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136285/2/jcb25768.pd

Self-reported impulsivity in women with borderline personality disorder: the role of childhood maltreatment severity and emotion regulation difficulties

Background: Childhood maltreatment, such as severe emotional, physical, and sexual abuse and neglect, has been linked to impulse control problems and dysfunctional emotional coping. In borderline personality disorder (BPD), a history of childhood maltreatment may worsen difficulties in emotion regulation, which may in turn give rise to impulsive behaviours. The aim of this self-report study was to investigate associations between childhood maltreatment severity, emotion regulation difficulties, and impulsivity in women with BPD compared to healthy and clinical controls. Methods: Sixty-one female patients with BPD, 57 clinical controls (CC, women with Attention Deficit Hyperactivity Disorder and/or Substance Use Disorder, without BPD), and 60 female healthy controls (HC) completed self-report scales on childhood trauma (Childhood Trauma Questionnaire, CTQ), difficulties in emotion regulation (Difficulties in Emotion Regulation Scale, DERS), and impulsivity (UPPS Impulsive Behaviour Scale). A conditional process analysis was performed to investigate whether emotion dysregulation statistically mediated the effect of childhood maltreatment severity on impulsivity depending on group (BPD vs. CC vs. HC). Results: Childhood maltreatment, particularly emotional maltreatment, was positively associated with impulsivity and emotion regulation difficulties across all groups. Difficulties in emotion regulation statistically mediated the effect of childhood maltreatment on impulsivity in BPD, but not in the other groups. Conclusion: In the context of current conceptualizations of BPD and previous research, findings suggest that problems with emotion regulation may be related to a history of childhood maltreatment, which may in turn enhance impulsivity. Targeting emotion dysregulation in psychotherapy and discussing it in relation to childhood maltreatment can help decreasing impulsive behaviors in individuals with BPD. Given the correlational design of our study which does not allow causal conclusions, future studies have to employ prospective, experimental designs and include larger sample sizes to corroborate associations between childhood maltreatment, emotion dysregulation, and impulsivity

Detection and isolation of disseminated tumor cells in bone marrow of patients with clinically localized prostate cancer

BackgroundDisseminated tumor cells (DTCs) have been reported in the bone marrow (BM) of patients with localized prostate cancer (PCa). However, the existence of these cells continues to be questioned, and few methods exist for viable DTC isolation. Therefore, we sought to develop novel approaches to identify and, if detected, analyze localized PCa patient DTCs.MethodsWe used fluorescence‐activated cell sorting (FACS) to isolate a putative DTC population, which was negative for CD45, CD235a, alkaline phosphatase, and CD34, and strongly expressed EPCAM. We examined tumor cell content by bulk cell RNA sequencing (RNA‐Seq) and whole‐exome sequencing after whole genome amplification. We also enriched for BM DTCs with α‐EPCAM immunomagnetic beads and performed quantitative reverse trancriptase polymerase chain reaction (qRT‐PCR) for PCa markers.ResultsAt a threshold of 4 cells per million BM cells, the putative DTC population was present in 10 of 58 patients (17%) with localized PCa, 4 of 8 patients with metastatic PCa of varying disease control, and 1 of 8 patients with no known cancer, and was positively correlated with patients’ plasma PSA values. RNA‐Seq analysis of the putative DTC population collected from samples above (3 patients) and below (5 patients) the threshold of 4 putative DTCs per million showed increased expression of PCa marker genes in 4 of 8 patients with localized PCa, but not the one normal donor who had the putative DTC population present. Whole‐exome sequencing also showed the presence of single nucleotide polymorphisms and structural variants in the gene characteristics of PCa in 2 of 3 localized PCa patients. To examine the likely contaminating cell types, we used a myeloid colony formation assay, differential counts of cell smears, and analysis of the RNA‐Seq data using the CIBERSORT algorithm, which most strongly suggested the presence of B‐cell lineages as a contaminant. Finally, we used EPCAM enrichment and qRT‐PCR for PCa markers to estimate DTC prevalence and found evidence of DTCs in 21 of 44 samples (47%).ConclusionThese data support the presence of DTCs in the BM of a subset of patients with localized PCa and describe a novel FACS method for isolation and analysis of viable DTCs.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151343/1/pros23896.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151343/2/pros23896_am.pd