Fibroblast Growth Factor 2 Regulates High Mobility Group A2 Expression in Human Bone Marrow-Derived Mesenchymal Stem Cells.

Mesenchymal stem cells (MSCs) are an excellent source for numerous cellular therapies due to their simple isolation, low immunogenicity, multipotent differentiation potential and regenerative secretion profile. However, over-expanded MSCs show decreased therapeutic efficacy. This shortcoming may be circumvented by identifying methods that promote self-renewal of MSCs in culture. HMGA2 is a DNA-binding protein that regulates self-renewal in multiple types of stem cells through chromatin remodeling, but its impact on human bone marrow-derived MSCs is not known. Using an isolation method to obtain pure MSCs within 9 days in culture, we show that expression of HMGA2 quickly decreases during early expansion of MSCs, while let-7 microRNAs (which repress HMGA2) are simultaneously increased. Remarkably, we demonstrate that FGF-2, a growth factor commonly used to promote self-renewal in MSCs, rapidly induces HMGA2 expression in a time- and concentration-dependent manner. The signaling pathway involves FGF-2 receptor 1 (FGFR1) and ERK1/2, but acts independent from let-7. By silencing HMGA2 using shRNAs, we demonstrate that HMGA2 is necessary for MSC proliferation. However, we also show that over-expression of HMGA2 does not increase cell proliferation, but rather abrogates the mitogenic effect of FGF-2, possibly through inhibition of FGFR1. In addition, using different methods to assess in vitro differentiation, we show that modulation of HMGA2 inhibits adipogenesis, but does not affect osteogenesis of MSCs. Altogether, our results show that HMGA2 expression is associated with highly proliferating MSCs, is tightly regulated by FGF-2, and is involved in both proliferation and adipogenesis of MSCs. J. Cell. Biochem. 117: 2128-2137, 2016. © 2016 Wiley Periodicals, Inc.

Mesenchymal Stem Cells Respond to Hypoxia by Increasing Diacylglycerols.

Mesenchymal stem cells (MSC) are currently being tested clinically for a plethora of conditions, with most approaches relying on the secretion of paracrine signals by MSC to modulate the immune system, promote wound healing, and induce angiogenesis. Hypoxia has been shown to affect MSC proliferation, differentiation, survival and secretory profile. Here, we investigate changes in the lipid composition of human bone marrow-derived MSC after exposure to hypoxia. Using mass spectrometry, we compared the lipid profiles of MSC derived from five different donors, cultured for two days in either normoxia (control) or hypoxia (1% oxygen). Hypoxia induced a significant increase of total triglycerides, fatty acids and diacylglycerols (DG). Remarkably, reduction of DG levels using the phosphatidylcholine-specific phospholipase C inhibitor D609 inhibited the secretion of VEGF and Angiopoietin-2, but increased the secretion of interleukin-8, without affecting significantly their respective mRNA levels. Functionally, incubation of MSC in hypoxia with D609 inhibited the potential of the cells to promote migration of human endothelial cells in a wound/scratch assay. Hence, we show that hypoxia induces in MSC an increase of DG that may affect the angiogenic potential of these cells.

Hypoxic preconditioning of mesenchymal stromal cells induces metabolic changes, enhances survival, and promotes cell retention in vivo.

Mesenchymal stem cells/multipotent stromal cells (MSCs) are promising therapeutics for a variety of conditions. However, after transplantation, cell retention remains extremely challenging. Given that many hypoxic signals are transitory and that the therapeutic administration of MSCs is typically into tissues that are normally hypoxic, we studied the effect of hypoxic preconditioning (HP) prior to new exposure to hypoxia. We show that preincubation for 2 days or more in 1% oxygen reduces serum deprivation-mediated cell death, as observed by higher cell numbers and lower incorporation of EthD-III and Annexin V. Consistently, HP-MSCs expressed significantly lower levels of cytochrome c and heme oxygenase 1 as compared to controls. Most importantly, HP-MSCs showed enhanced survival in vivo after intramuscular injection into immune deficient NOD/SCID-IL2Rgamma(-/-) mice. Interestingly, HP-MSCs consume glucose and secrete lactate at a slower rate than controls, possibly promoting cell survival, as glucose remains available to the cells for longer periods of time. In addition, we compared the metabolome of HP-MSCs to controls, before and after hypoxia and serum deprivation, and identified several possible mediators for HP-mediated cell survival. Overall, our findings suggest that preincubation of MSCs for 2 days or more in hypoxia induces metabolic changes that yield higher retention after transplantation.

Cross-sectional comparison of health care delivery and reimbursement between segregated and nonsegregated communities in Hungary.

Introduction: Spatially segregated, socio-economically deprived communities in Europe are at risk of being neglected in terms of health care. In Hungary, poor monitoring systems and poor knowledge on the health status of people in these segregated areas prevent the development of well-informed effective interventions for these vulnerable communities. Aims: We used data available from National Health Insurance Fund Management to better describe health care performance in segregated communities and to develop more robust monitoring systems. Methods: A cross-sectional study using 2020 health care data was conducted on each general medical practice (GMP) in Hungary providing care to both segregated and nonsegregated (complementary) adult patients. Segregated areas were mapped and ascertained by a governmental decree that defines them as within settlement clusters of adults with low level of education and income. Age, sex, and eligibility for exemption certificate standardized indicators for health care delivery, reimbursement, and premature mortality were computed for segregated and nonsegregated groups of adults and aggregated at the country level. The ratio of segregation and nonsegregation specific indicators (relative risk, RR) was computed with the corresponding 95% confidence intervals (95% CI). Results: Broad variations between GMPs were detected for each indicator. Segregated groups had a significantly higher rate of health care service use than complementary groups (RR = 1.22, 95% CI: 1.219;1.223) while suffering from significantly reduced health care reimbursement (RR = 0.940, 95% CI: 0.929;0.951). The risk of premature mortality was significantly higher among segregated patients (RR = 1.184, 95% CI: 1.087;1.289). Altogether, living in a segregated area led to an increase in visits to health care services by 18.1% with 6.6% less health spending. Conclusion: Adults living in segregated areas use health care services more frequently than those living in nonsegregated areas; however, the amount of health care reimbursement they receive is significantly lower, suggesting lower quality of care. The health status of segregated adults is remarkably lower, as evidenced by their higher premature mortality rate. These findings demonstrate the need for intervention in this vulnerable group. Because our study reveals serious variation across GMPs, segregation-specific monitoring is necessary to support programs sensitive to local issues and establish necessary benchmarks.

[Thromboembolic complications associated to malignant diseases]. / A malignus betegségekhez társuló tromboembóliás szövodmények.

Cancers are known to increase the tendency for thrombosis, both on the venous and arterial side, which to this day is an important factor in the management of oncology patients. Malignant disease is an independent risk factor for developing venous thromboembolism (VTE). Thromboembolic complications in addition to the disease worsen prognosis and are accompanied by significant morbidity and mortality. VTE is the second most common cause of death in cancer after disease progression. Tumors are characterized by hypercoagulability, in addition to which venous stasis and endothelial damage also occur in cancer patients promoting increased clotting. Treatment of cancer-associated thrombosis is often complex; therefore, it is important to identify patients who benefit from primary thromboprophylaxis. The importance of cancer-associated thrombosis is indisputable in everyday oncology. We briefly summarize the frequency and characteristics of their occurrence, the underlying mechanisms, risk factors, clinical appearance, laboratory diagnostics, and the possibilities of prevention and treatment.

Delayed Gelatinase Inhibition Induces Reticulon 4 Receptor Expression in the Peri-Infarct Cortex.

Matrix metalloproteinase (MMP) inhibition can potentially prevent hemorrhagic transformation following cerebral infarction; however, delayed-phase MMP activity is also necessary for functional recovery after experimental stroke. We sought to identify potential mechanisms responsible for the impaired recovery associated with subacute MMP inhibition in a transient middle cerebral artery occlusion model of focal ischemia in CD rats. Gelatinase inhibition was achieved by intracerebral injection of the Fn-439 MMP inhibitor 7 days after stroke. Treatment efficacy was determined on day 9 by in situ gelatin zymography. The peri-infarct cortex was identified by triphenyl tetrazolium chloride staining, and tissue samples were dissected for TaqMan array gene-expression study. Of 84 genes known to influence poststroke regeneration, we found upregulation of mRNA for the reticulon 4 receptor (Rtn4r), a major inhibitor of regenerative nerve growth in the adult CNS, and borderline expression changes for 3 additional genes (DCC, Jun, and Ngfr). Western blot confirmed increased Rtn4r protein in the peri-infarct cortex of treated animals, and double immunolabeling showed colocalization primarily with the S100 astrocyte marker. These data suggest that increased Rtn4 receptor expression in the perilesional cortex may contribute to the impaired regeneration associated with MMP inhibition in the subacute phase of cerebral infarction.

Selegiline promotes NOTCH-JAGGED signaling in astrocytes of the peri-infarct region and improves the functional integrity of the neurovascular unit in a rat model of focal ischemia.

PURPOSE: Our experiments aimed at exploring potential neurorestorative mechanisms of selegiline, a compound routinely used in the treatment of Parkinson's disease and previously shown to improve the functional recovery of stroke patients. METHODS: Selegiline was administered continuously via osmotic mini-pumps between 48 and 216 hours following middle cerebral artery occlusion (MCAO) in rats. Twenty-four hours before sacrifice, the animals underwent magnetic resonance imaging (MRI). After decapitation, the peri-infarct region was dissected to perform a TAQMAN array gene expression study, and brains were fixed for immunolabeling. RESULTS: In addition to the previously known induction of anti-apoptosis genes, selegiline significantly increased the mRNA level of Notch 1 receptor and its ligand Jagged 1. Immunohistochemistry demonstrated elevated Notch 1 and Jagged 1 immunoreactivities in the peri-infarct region. Double labeling with glial markers revealed that both Notch 1 and Jagged 1 were expressed in astrocytes but not in microglia. MRI examination indicated significantly reduced edema in selegiline-treated rats compared to control MCAO rats, and increased capillary network density was found in the peri-infarct region of the selegiline-treated animals. CONCLUSION: Our results suggest that selegiline treatment enhances Notch-Jagged signaling in astrocytes, reduces peri-lesional edema and potentially helps preserve the capillary network following focal ischemia.