Martin Luther University of Halle-Wittenberg

About: Martin Luther University of Halle-Wittenberg is a education organization based out in Halle, Germany. It is known for research contribution in the topics: Population & Liquid crystal. The organization has 20232 authors who have published 38773 publications receiving 965004 citations. The organization is also known as: MLU & University of Wittenberg.

Human CD133+ Progenitor Cells Promote the Healing of Diabetic Ischemic Ulcers by Paracrine Stimulation of Angiogenesis and Activation of Wnt Signaling

Abstract: We evaluated the healing potential of human fetal aorta-derived CD133(+) progenitor cells and their conditioned medium (CD133(+) CCM) in a new model of ischemic diabetic ulcer. Streptozotocin-induced diabetic mice underwent bilateral limb ischemia and wounding. One wound was covered with collagen containing 2x10(4) CD133(+) or CD133(-) cells or vehicle. The contralateral wound, covered with only collagen, served as control. Fetal CD133(+) cells expressed high levels of wingless (Wnt) genes, which were downregulated following differentiation into CD133(-) cells along with upregulation of Wnt antagonists secreted frizzled-related protein (sFRP)-1, -3, and -4. CD133(+) cells accelerated wound closure as compared with CD133(-) or vehicle and promoted angiogenesis through stimulation of endothelial cell proliferation, migration, and survival by paracrine effects. CD133(+) cells secreted high levels of vascular endothelial growth factor (VEGF)-A and interleukin (IL)-8. Consistently, CD133(+) CCM accelerated wound closure and reparative angiogenesis, with this action abrogated by co-administering the Wnt antagonist sFRP-1 or neutralizing antibodies against VEGF-A or IL-8. In vitro, these effects were recapitulated following exposure of high-glucose-primed human umbilical vein endothelial cells to CD133(+) CCM, resulting in stimulation of migration, angiogenesis-like network formation and induction of Wnt expression. The promigratory and proangiogenic effect of CD133(+) CCM was blunted by sFRP-1, as well as antibodies against VEGF-A or IL-8. CD133(+) cells stimulate wound healing by paracrine mechanisms that activate Wnt signaling pathway in recipients. These preclinical findings open new perspectives for the cure of diabetic ulcers.

Semicrystalline morphology in thin films of poly(3-hexylthiophene)

Abstract: The thermodynamic phase behavior and the morphology in thin films of poly(3-hexylthiophene) (P3HT) has been studied using calorimetry, X-ray scattering, and scanning force microscopy (AFM). Around 225 °C a phase transition from the crystalline state to a layered, liquid crystalline structure occurs in regioregular P3HT, while the regiorandom counterpart material is disordered at all temperatures and displays a glass transition temperature T g ≈−3 °C. Regioregular P3HT is semicrystalline and forms needle or plate like crystallites which in solution cast thin films are oriented with respect to the substrate. Films produced by spin coating display a non-equilibrium structure with reduced order and orientation. Annealing of these films in the liquid crystalline state leads to the formation of a morphology similar to the one observed in solution cast films.

IGF2BP1 promotes SRF-dependent transcription in cancer in a m6A- and miRNA-dependent manner

Abstract: The oncofetal mRNA-binding protein IGF2BP1 and the transcriptional regulator SRF modulate gene expression in cancer. In cancer cells, we demonstrate that IGF2BP1 promotes the expression of SRF in a conserved and N6-methyladenosine (m6A)-dependent manner by impairing the miRNA-directed decay of the SRF mRNA. This results in enhanced SRF-dependent transcriptional activity and promotes tumor cell growth and invasion. At the post-transcriptional level, IGF2BP1 sustains the expression of various SRF-target genes. The majority of these SRF/IGF2BP1-enhanced genes, including PDLIM7 and FOXK1, show conserved upregulation with SRF and IGF2BP1 synthesis in cancer. PDLIM7 and FOXK1 promote tumor cell growth and were reported to enhance cell invasion. Consistently, 35 SRF/IGF2BP1-dependent genes showing conserved association with SRF and IGF2BP1 expression indicate a poor overall survival probability in ovarian, liver and lung cancer. In conclusion, these findings identify the SRF/IGF2BP1-, miRNome- and m6A-dependent control of gene expression as a conserved oncogenic driver network in cancer.

Lags in the response of mountain plant communities to climate change

Abstract: Rapid climatic changes and increasing human influence at high elevations around the world will have profound impacts on mountain biodiversity. However, forecasts from statistical models (e.g. species distribution models) rarely consider that plant community changes could substantially lag behind climatic changes, hindering our ability to make temporally realistic projections for the coming century. Indeed, the magnitudes of lags, and the relative importance of the different factors giving rise to them, remain poorly understood. We review evidence for three types of lag: "dispersal lags" affecting plant species' spread along elevational gradients, "establishment lags" following their arrival in recipient communities, and "extinction lags" of resident species. Variation in lags is explained by variation among species in physiological and demographic responses, by effects of altered biotic interactions, and by aspects of the physical environment. Of these, altered biotic interactions could contribute substantially to establishment and extinction lags, yet impacts of biotic interactions on range dynamics are poorly understood. We develop a mechanistic community model to illustrate how species turnover in future communities might lag behind simple expectations based on species' range shifts with unlimited dispersal. The model shows a combined contribution of altered biotic interactions and dispersal lags to plant community turnover along an elevational gradient following climate warming. Our review and simulation support the view that accounting for disequilibrium range dynamics will be essential for realistic forecasts of patterns of biodiversity under climate change, with implications for the conservation of mountain species and the ecosystem functions they provide.