| 25 |
Presenter: Dan Debra
Time: 12:30 pm – 1:30 pm
Location: BST S218
Topic: Relaxin Regulates Systemic Hemodynamics and Arterial and Vascular Wall Mechanical Properties
Description: Relaxin is a peptide hormone that emanates from the corpus luteum of the ovary and circulates during pregnancy. Our previous work has shown that the hormone mediates the transition of the systemic circulation from the virgin to the pregnant state in the gravid rat model. However, our recent work suggests that relaxin’s effects on the systemic circulation extend beyond pregnancy. Specifically, we have shown that relaxin regulates systemic hemodynamics as well as vascular structure and mechanical properties in nonpregnant female and male rodents. In addition, relaxin receptors have been detected at various vascular sites in male and female species and relaxin knockout mice have a phenotype that is opposite to that observed during pregnancy and relaxin administration. In this seminar I will be discussing the effects of relaxin (both endogenously derived and exogenously administered) on systemic hemodynamics and vascular remodeling as well as the therapeutic potential for relaxin in modifying arterial stiffness and cardiac afterload. |
| 8 |
Presenter: Jörg C. Gerlach
Time: 12:30 pm – 1:30 pm
Location: BST S218
Topic: 3D perfusion bioreactor technologies for stem cell maintenance, differentiation and expansion in regenerative medicine
Description: Tissue density bioreactors enable a spontaneous re-assembly of primary cells inoculated into a bioreactor and their establishment of a scaffold or biomatrix. A homogeneous mix of adult liver cells, e.g. from organ collagenase digestion containing parenchymal hepatocytes, non-parenchymal cells (such as sinusoidal endothelial cells, stellate cells, and liver progenitor cells) can restructure after injection into specific bioreactors to form well-defined liver structures, such as neo-sinusoidal structures and neo-spaces of Dissé, reminiscent of the native liver. Moreover, adult liver progenitors restructure anatomical structures resembling the Canal of Hering, the putative liver stem cell niche.
The current challenge that prevents stem cells from use in regenerative medicine applications is directing the full differentiation of their progeny in vitro. In order to further develop new therapies, adult and embryonic stem cell research focuses on maintenance, proliferation and differentiation, and tissue formation in vitro. Numerous groups already work on derivation and characterization of specific stem cell lineages, but the underlying mechanisms are only partly understood.
Several fundamental questions remain to be answered, e.g.:
- Can we control proliferation/differentiation of selected stem cells in vitro?
- Can we maintain the genotype/phenotype stability of selected stem cells in vitro?
- Can specific micro-environmental conditions be used to control in vitro maintenance of selected stem cells?
- Can, after inoculation of selected isolated stem cells, tissue restructuring be achieved by the cells themselves?
- Can tissue formation by selected stem cells be induced and controlled in vitro?
- Can we establish in vitro a tissue-density of a larger number of selected stem cells without central necrosis?
- Can a reproducible proliferation/differentiation and utilization of selected stem cells be achieved in vitro?
- Can specific macro-environmental conditions, such as 3D high-density co-culture with integrated oxygenation and decentralized mass exchange, be used to control in vitro maintenance of human embryonic stem cells in a larger cell mass?
- Can a phenotypic stabilization of selected stem cells and the maintenance of a liver progenitor cell pool be achieved by 3D high-density co-culture with integrated oxygenation and decentralized mass exchange?
- Does the integration of a more physiological tissue macro-environment, e.g. by hollow fiber membranes into a growing cell mass result in a genotypic/phenotypic stabilization of proliferating stem cells?
- Can we maintain the stability of human embryonic stem cells in vitro, while they are proliferating as a larger mass and differentiating towards hepatic cells?
For several topics, experimental animal source or biopsied human tissue, as well as conventional Petri- dish in vitro culture methods seem to provide appropriate tools for investigation. However, investigations focusing on the impact of exogenous factors could benefit from the use of purpose-built bioreactors that enable 3D high-density perfusion co-culture. There is a considerable need for such in vitro stem cell systems, since the stem cell-derived tissues must be capable of stable and long-term integration; into a bioreactor or, after transplantation, into existing physiological tissues, at least until they are replaced by the body’s own tissue repair process, or permanently if self-repair is not possible. At least some of such studies require reproducible and controllable in vitro conditions. |
| 28 |
Presenter: Christi L. Kolarcik
Time: 12:30 pm - 1:30 pm
Location: BST S218
Topic: Characterization of retinoid signaling proteins in amyotrophic lateral sclerosis
Description: Amyotrophic lateral sclerosis (ALS), a fatal neuromuscular disorder and the most common form of motor neuron disease, is characterized by the progressive degeneration and death of motor neurons within the brain, brain stem and spinal cord. Currently, established and objective molecular markers that allow for the diagnosis and monitoring of ALS are lacking and improved therapeutic interventions needed. Our laboratory previously identified transthyretin (TTR) as a potential protein biomarker of ALS using mass spectrometry-based proteomics to profile cerebrospinal fluid of ALS and control subjects. TTR functions within the retinoid signaling pathway important for modulating gene expression and protein aggregation. This talk will discuss our characterization of retinoid signaling proteins in ALS. We hope to provide much-needed insight into the molecular mechanisms underlying this condition and to identify novel targets for future therapeutic investigations for the treatment of ALS. |
| 4 |
Presenter: Lance Davidson
Time: 12:30 pm – 1:30 pm
Location: BST S218
Topic: Reverse-Engineering Morphogenesis
Description: The control of morphogenesis is one of the most complex problems of modern biology and tissue engineering. Morphogenesis requires the coordination of tissue mechanics with cellular processes such as motility and shape changes. Advances have been made to understand the molecular regulation of cell motility, patterning, and signal transduction, yet little is understood about how these regulators control the mechanical process of morphogenesis. In order to understand the physical as well as the molecular regulators of morphogenesis we are working to "reverse-engineer" morphogenetic movements in frog embryos by applying advanced imaging, cell biological, biophysical, and bioengineering techniques at a number of different scales. |
