The chemokine stromal cell-derived factor-1α (SDF-1α) is a pivotal player in angiogenesis. It is capable of influencing such cellular processes as tubulogenesis and endothelial cell migration, yet ...very little is known about the actual signaling events that mediate SDF-1α-induced endothelial cell function. In this report, we describe the identification of an intricate SDF-1α-induced signaling cascade that involves endothelial nitric oxide synthase (eNOS), JNK3, and MAPK phosphatase 7 (MKP7). We demonstrate that the SDF-1α-induced activation of JNK3, critical for endothelial cell migration, depends on the prior activation of eNOS. Specifically, activation of eNOS leads to production of NO and subsequent nitrosylation of MKP7, rendering the phosphatase inactive and unable to inhibit the activation of JNK3. These observations reinforce the importance of nitric oxide and S-nitrosylation in angiogenesis and provide a mechanistic pathway for SDF-1α-induced endothelial cell migration. In addition, the discovery of this interactive network of pathways provides novel and unexpected therapeutic targets for angiogenesis-dependent diseases.
The bone morphogenetic protein (BMP) signaling pathway plays a central role during vasculature development. Mutations or dysregulation of the BMP pathway members have been linked to arteriovenous ...malformations. In the present study, we investigated the effect of the BMP modulators bone morphogenetic protein endothelial precursor‐derived regulator (BMPER) and twisted gastrulation protein homolog 1 (TWSG1) on arteriovenous specification during zebrafish development and analyzed downstream Notch signaling pathway in human endothelial cells. Silencing of bmper and twsg1b in zebrafish embryos by morpholinos resulted in a pronounced enhancement of venous ephrinB4a marker expression and concomitant dysregulated arterial ephrinb2a marker expression detected by in situ hybridization. As arteriovenous specification was disturbed, we assessed the impact of BMPER and TWSG1 protein stimulation on the Notch signaling pathway on endothelial cells from different origin. Quantitative real‐time PCR (qRT‐PCR) and western blot analysis showed increased expression of Notch target gene hairy and enhancer of split, HEY1/2 and EPHRINB2. Consistently, silencing of BMPER in endothelial cells by siRNAs decreased Notch signaling and downstream effectors. BMP receptor antagonist DMH1 abolished BMPER and BMP4 induced Notch signaling pathway activation. In conclusion, we found that in endothelial cells, BMPER and TWSG1 are necessary for regular Notch signaling activity and in zebrafish embryos BMPER and TWSG1 preserve arteriovenous specification to prevent malformations.
The bone morphogenetic protein (BMP) signaling pathway plays a central role during vasculature development. Silencing of bmper and twsg1b in zebrafish embryos by morpholinos resulted in increased venous ephrinB4a and concomitant dysregulated arterial ephrinb2a marker expression, which was confirmed in human endothelial cells. Silencing of bone morphogenetic protein endothelial precursor‐derived regulator or application of BMP inhibitor dorsomorphin homolog 1 prevented Notch pathway activation and increased ephrin receptor b4a expression.
Blood vessel formation requires the integrated regulation of endothelial cell proliferation and branching morphogenesis, but how this coordinated regulation is achieved is not well understood. Flt-1 ...(vascular endothelial growth factor VEGF receptor 1) is a high affinity VEGF-A receptor whose loss leads to vessel overgrowth and dysmorphogenesis. We examined the ability of Flt-1 isoform transgenes to rescue the vascular development of embryonic stem cell-derived flt-1⁻/⁻ mutant vessels. Endothelial proliferation was equivalently rescued by both soluble (sFlt-1) and membrane-tethered (mFlt-1) isoforms, but only sFlt-1 rescued vessel branching. Flk-1 Tyr-1173 phosphorylation was increased in flt-1⁻/⁻ mutant vessels and partially rescued by the Flt-1 isoform transgenes. sFlt-1-rescued vessels exhibited more heterogeneous levels of pFlk than did mFlt-1-rescued vessels, and reporter gene expression from the flt-1 locus was also heterogeneous in developing vessels. Our data support a model whereby sFlt-1 protein is more efficient than mFlt-1 at amplifying initial expression differences, and these amplified differences set up local discontinuities in VEGF-A ligand availability that are important for proper vessel branching.
Mutation in leucine-rich repeat kinase-2 (LRRK2) is the most common cause of late-onset Parkinson's disease (PD). Although most cases of PD are sporadic, some are inherited, including those caused by ...LRRK2 mutations. Because these mutations may be associated with a toxic gain of function, controlling the expression of LRRK2 may decrease its cytotoxicity. Here we show that the carboxyl terminus of HSP70-interacting protein (CHIP) binds, ubiquitinates, and promotes the ubiquitin proteasomal degradation of LRRK2. Overexpression of CHIP protects against and knockdown of CHIP exacerbates toxicity mediated by mutant LRRK2. Moreover, HSP90 forms a complex with LRRK2, and inhibition of HSP90 chaperone activity by 17AAG leads to proteasomal degradation of LRRK2, resulting in increased cell viability. Thus, increasing CHIP E3 ligase activity and blocking HSP90 chaperone activity can prevent the deleterious effects of LRRK2. These findings point to potential treatment options for LRRK2-associated PD.
Heart Healthy Lenoir is a transdisciplinary project aimed at creating long-term, sustainable approaches to reduce cardiovascular disease risk disparities in Lenoir County, North Carolina using a ...design spanning genomic analysis and clinical intervention. We hypothesized that residents of Lenoir County would be unfamiliar and mistrustful of genomic research, and therefore reluctant to participate; additionally, these feelings would be higher in African-Americans.
To test our hypothesis, we conducted qualitative research using community-based participatory research principles to ensure our genomic research strategies addressed the needs, priorities, and concerns of the community. African-American (n = 19) and White (n = 16) adults in Lenoir County participated in four focus groups exploring perceptions about genomics and cardiovascular disease. Demographic surveys were administered and a semi-structured interview guide was used to facilitate discussions. The discussions were digitally recorded, transcribed verbatim, and analyzed in ATLAS.ti.
From our analysis, key themes emerged: transparent communication, privacy, participation incentives and barriers, knowledge, and the impact of knowing. African-Americans were more concerned about privacy and community impact compared to Whites, however, African-Americans were still eager to participate in our genomic research project. The results from our formative study were used to improve the informed consent and recruitment processes by: 1) reducing misconceptions of genomic studies; and 2) helping to foster participant understanding and trust with the researchers. Our study demonstrates how community-based participatory research principles can be used to gain deeper insight into the community and increase participation in genomic research studies. Due in part to these efforts 80.3% of eligible African-American participants and 86.9% of eligible White participants enrolled in the Heart Healthy Lenoir Genomics study making our overall enrollment 57.8% African-American. Future research will investigate return of genomic results in the Lenoir community.
Research to Revenue Rose, Don; Patterson, Cam; Boyer, Herbert W
01/2016
eBook
University start-ups are unique in the world of business and entrepreneurship, translating research conducted at and owned by universities into market-ready products--a complex process that requires ...a combination of scientific, technical, legal, business, and financial skills to be successful. Start-ups have the potential to generate revenue for universities, enhance faculty recruitment and retention, create jobs, and create investment opportunities for venture capitalists and entrepreneurs.Research to Revenuepresents the first-ever comprehensive guide to understanding, starting, and managing university startups. By systematically describing the process of translating academic research into commercial enterprises, Don Rose and Cam Patterson give a thorough, process-oriented, and practical set of guidelines that cover not only best practices but also common--and avoidable--mistakes. They detail the key factors and components that contribute to a successful start-up, explain what makes university start-ups unique, delineate the steps of building and managing them, and describe how to foster and maintain start-ups at a university. Written for faculty and staff working on campus, tech-transfer officers, university administrators, and venture capitalists unfamiliar with university structures,Research to Revenueensures that any reader unfamiliar with technology commercialization and entrepreneurship will understand the fundamentals of the process, including intellectual property rights, fund-raising, and business models. This work is an invaluable resource for the successful formation and well-managed operation of university start-ups.
Bone morphogenetic proteins (BMPs) are involved in embryonic and adult blood vessel formation in health and disease. BMPER (BMP endothelial cell precursor-derived regulator) is a differentially ...expressed protein in embryonic endothelial precursor cells. In earlier work, we found that BMPER interacts with BMPs and when overexpressed antagonizes their function in embryonic axis formation. In contrast, in a BMPER-deficient zebrafish model, BMPER behaves as a BMP agonist. Furthermore, lack of BMPER induces a vascular phenotype in zebrafish that is driven by disarray of the intersomitic vasculature. Here, we investigate the impact of BMPER on endothelial cell function and signaling and elucidate its role in BMP-4 function in gain- and loss-of-function models. As shown by Western blotting and immunocytochemistry, BMPER is an extracellular matrix protein expressed by endothelial cells in skin, heart, and lung. We show that BMPER is a downstream target of FoxO3a and consistently exerts activating effects on endothelial cell sprouting and migration in vitro and in vivo. Accordingly, when BMPER is depleted from endothelial cells, sprouting is impaired. In terms of BMPER related intracellular signaling, we show that BMPER is permissive and necessary for Smad 1/5 phosphorylation and induces Erk1/2 activation. Most interestingly, BMPER is necessary for BMP-4 to exert its activating role in endothelial function and to induce Smad 1/5 activation. Vice versa, BMP-4 is necessary for BMPER activity. Taken together, BMPER is a dose-dependent endothelial cell activator that plays a unique and pivotal role in fine-tuning BMP activity in angiogenesis.
Tacrolimus (FK506) is an immunosuppressive drug that binds to the immunophilin FKBPB12. The FK506-FKBP12 complex associates with calcineurin and inhibits its phosphatase activity, resulting in ...inhibition of nuclear translocation of nuclear factor of activated T-cells (NFAT). There is increasing data supporting a critical role of NFAT in mediating angiogenic responses stimulated by both vascular endothelial growth factor (VEGF) and a novel angiogenesis factor, secreted frizzled-related protein 2 (SFRP2). Since both VEGF and SFRP2 are expressed in breast carcinomas, we hypothesized that tacrolimus would inhibit breast carcinoma growth. Using IHC (IHC) with antibodies to FKBP12 on breast carcinomas we found that FKBP12 localizes to breast tumor vasculature. Treatment of MMTV-neu transgenic mice with tacrolimus (3 mg/kg i.p. daily) (n = 19) resulted in a 73% reduction in the growth rate for tacrolimus treated mice compared to control (n = 15), p = 0.003; which was associated with an 82% reduction in tumor microvascular density (p<0.001) by IHC. Tacrolimus (1 µM) inhibited SFRP2 induced endothelial tube formation by 71% (p = 0.005) and inhibited VEGF induced endothelial tube formation by 67% (p = 0.004). To show that NFATc3 is required for SFRP2 stimulated angiogenesis, NFATc3 was silenced with shRNA in endothelial cells. Sham transfected cells responded to SFRP2 stimulation in a tube formation assay with an increase in the number of branch points (p<0.003), however, cells transfected with shRNA to NFATc3 showed no increase in tube formation in response to SFRP2. This demonstrates that NFATc3 is required for SFRP2 induced tube formation, and tacrolimus inhibits angiogenesis in vitro and breast carcinoma growth in vivo. This provides a rationale for examining the therapeutic potential of tacrolimus at inhibiting breast carcinoma growth in humans.
Growth and regeneration of blood vessels are crucial processes during embryonic development and in adult disease. Members of the bone morphogenetic protein (BMP) family are growth factors known to ...play a key role in vascular development. The BMP pathway is controlled by extracellular BMP modulators such as BMP endothelial cell precursor derived regulator (BMPER), which we reported previously acts proangiogenically on endothelial cells in a concentration-dependent manner. Here, we explore the function of other BMP modulators, especially Tsg, on endothelial cell behaviour and compare them to BMPER. In Matrigel assays, BMP modulators chordin and noggin had no stimulatory effect; however, gremlin and Tsg enhanced human umbilical vein endothelial cell (HUVEC) sprouting. As the activation dynamics of Tsg were similar to those of BMPER, we further investigated the proangiogenic effect of Tsg on endothelial cells. Tsg enhanced endothelial cell ingrowth in the mouse Matrigel plug assay as well as HUVEC sprouting, migration and proliferation in vitro, dependent on Akt, Erk and Smad signalling pathway activation in a concentration-dependent manner. Surprisingly, silencing of Tsg also increased HUVEC sprouting, migration and proliferation, which is again associated with Akt, Erk and Smad signalling pathway activation. Furthermore, we reveal that Tsg and BMPER interfere with each other to enhance proangiogenic events. However, in vivo the presence of Tsg as well as of BMPER is mandatory for regular development of the zebrafish vasculature. Taken together, our results suggest that BMPER and Tsg maintain a fine-tuned equilibrium that controls BMP pathway activity and is necessary for vascular cell homeostasis.
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