Effect of HBO therapy on adipose-derived stem cells, fibroblasts and co-cultures: In vitro study of oxidative stress, angiogenic potential and production of pro-inflammatory growth factors in co-cultures1

BACKGROUND: A key moderator of wound healing is oxygen. Wound healing is a dynamic and carefully orchestrated process involving blood cells, cytokines, parenchymal cells (i.e. fibroblasts and mesenchymal stem cells) and extracellular matrix reorganization. Human adipose derived stem cells as well as human fibroblasts produce soluble factors, exhibit diverse effects on inflammation and anti inflammation response and are involved in wound healing processes. Hyperbaric oxygen therapy is an effective adjunct treatment for ischemic disorders such as chronic infection or chronic wounds. In vitro effects of hyperbaric oxygen therapy on human cells were presented in many studies except for those on mono- and co-cultures of human adipose derived stem cells and fibroblasts. OBJECTIVE: The aim of this study was to investigate the effects of hyperbaric oxygen therapy on mono- and co-cultures of human adipose derived stem cells and fibroblasts. METHODS: Mono- and co-cultures from human adipose derived stem cells and fibroblasts were established. These cultures were exposed to hyperbaric oxygen therapy every 24 h for five consecutive days. Measuring experiments were performed on the first, third and fifth day. Therapy effects on the expression of VEGF, IL 6 and reactive oxygen species were investigated. RESULTS: After exposure to hyperbaric oxygen, cell culturess showed a significant increase in the expression of VEGF after 3 and 5 days. All cultures showed significantly reduced formation of reactive oxygen species throughout the experiments. The expression of IL-6 decreased during the experiment in mono-cultures of human adipose derived stem cells and co-cultures. In contrast, mono-cultures of human skin fibroblasts showed an overall significantly increased expression of IL-6. CONCLUSIONS: Hyperbaric oxygen therapy leads to immunmodulatory and proangiogenetic effects in a wound-like enviroment of adipose derived stem cells and fibroblasts.

[Various scenarios for billing and remuneration of preoperative management of iron deficiency anemia in the German healthcare system]

More than 30% of all patients undergoing surgery suffer from preoperative anemia. Iron deficiency anemia is the most common type of anemia. The diagnostics and treatment of iron deficiency anemia can be carried out before patients undergo surgery as an alternative to blood transfusion and is an interdisciplinary task. This article gives an overview of various billing modalities and payment arrangements for management of preoperative anemia in the German healthcare system.

Environmental stimuli shape microglial plasticity in glioma

In glioma, microglia and infiltrating macrophages are exposed to factors that force them to produce cytokines and chemokines, which contribute to tumor growth and to maintaining a pro-tumorigenic, immunosuppressed microenvironment. We demonstrate that housing glioma-bearing mice in enriched environment (EE) reverts the immunosuppressive phenotype of infiltrating myeloid cells, by modulating inflammatory gene expression. Under these conditions, the branching and patrolling activity of myeloid cells is increased, and their phagocytic activity is promoted. Modulation of gene expression depends on interferon-(IFN)-γ produced by natural killer (NK) cells. This modulation disappears in mice depleted of NK cells or lacking IFN-γ, and was mimicked by exogenous interleukin-15 (IL-15). Further, we describe a key role for brain-derived neurotrophic factor (BDNF) that is produced in the brain of mice housed in EE, in mediating the expression of IL-15 in CD11b⁺ cells. These data define novel mechanisms linking environmental cues to the acquisition of a pro-inflammatory, anti-tumor microenvironment in mouse brain.

[Analysis and options for optimization of preoperative assessment for anesthesia at a university hospital]

BACKGROUND

Risk assessment prior to elective surgery is an important tool in the context of perioperative patient care; however, only a few studies have been carried out to address the processes and problems during preoperative assessment for anesthesia.

AIM

Over a period of several weeks all preoperative anesthesia evaluations prior to elective surgery were prospectively recorded in order to generate a data pool with a view to identifying options for process optimization.

MATERIAL AND METHODS

All preoperative evaluations over a period of 38 working days at the University Medical Center Regensburg were recorded and analyzed with respect to waiting time for the patient and the duration of the preoperative consultation on medication. Also documented were the patient age, ASA score, the faculty carrying out the operation, type and risk of surgery, planned time of surgery, professional experience of the anesthesiologist and the approval status for surgery. In addition, all problems which occurred during the preoperative anesthesia evaluation were documented using a questionnaire.

RESULTS

Overall 2233 preoperative assessments for anesthesia were recorded and analyzed. The number of patients attending the preoperative assessment clinic differed markedly in the course of a day and was lower at the end of the week. Approval for surgery with no reservations was given more frequently by anesthesiologists with more than 5 years professional experience and consultants compared to younger colleagues. The main reason for approval with reservations or no approval was the lack of patient records and test results, which should have been presented according to the in-house standard for preoperative assessment for anesthesia. The mean waiting time was 58.6 ± 30.3 min, the mean duration of the patient documentation review and physician-patient consultation together was 33.6 ± 16.3 min. Anesthesiologists with 2-5 years professional experience needed significantly less time for patient documentation reviews and physician-patient consultations than younger and more experienced colleagues. The duration of the preoperative assessment for anesthesia correlated with the ASA score and risks of surgery.

CONCLUSION

The analysis of processes and problems in the context of preoperative assessment for anesthesia revealed several options for optimization. Major efforts should be the implementation of an appointment system for the preoperative assessment clinic in order to generate a homogeneous distribution of patients during the course of a day. Furthermore, surgeons and case managers should be requested to refer patients to the preoperative assessment clinic only with complete records and test results according to the in-house standard.

Abstract 1159: Ketosis and hyperbaric oxygen elicit potent anti-cancer effects in vitro and in vivo

The Warburg effect and tumor hypoxia underlie a unique cancer metabolism characterized by glucose dependency and abnormal mitochondrial function. We have previously shown that this phenotype can be exploited therapeutically by glucose restriction with the ketogenic diet, dietary ketone supplementation, or hyperbaric oxygen (HBOT). We hypothesized that combining these therapies would be an effective non-toxic treatment regimen, so we tested this combination therapy in the VM-M3 mouse model of metastatic cancer. Treated mice exhibited decreased tumor growth rate, decreased metastatic spread to the lungs, kidneys, spleen, adipose, and liver, decreased liver tumor vascularization, and lived twice as long as controls. To further characterize the effects of these therapies, we measured proliferation, viability, ROS production, and expression of key signaling molecules in VM-M3 cells exposed to the following conditions: high glucose (control; 25mM), low glucose (LG; 3mM), ketone supplementation (βHB; 5mM), hyperbaric oxygen (HBOT; 90 min, 2.5 ATA), or combination therapy (LG+BHB+HBOT). Proliferation of VM-M3 cells was measured with trypan blue hemocytometry and was significantly decreased from controls at 24, 48, 72, and 96 hours. Viability of VM-M3 cells was measured by fluorescence microscopy with calcein and EthD-1 and was decreased by 19.2% in LG, 12.5% in βHB, and 38.2% in LG+βHB+HBOT treated cells compared to control. ROS (superoxide) production was measured by fluorescent microscopy with DHE and was increased by 46% in HBOT and by 48% in LG+βHB+HBOT treated cells. Treatment with βHB significantly decreased expression of HIF-1α and pAkt compared to control as measured with western blot. HBOT also inhibited HIF-1α expression but increased pAkt expression in vitro. This study strongly supports further investigation into mechanisms of action and the use of these metabolic therapies as a potential cancer treatment.

Citation Format: Angela Poff, Nathan Ward, Thomas Seyfried, Dominic D'Agostino. Ketosis and hyperbaric oxygen elicit potent anti-cancer effects in vitro and in vivo. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1159. doi:10.1158/1538-7445.AM2015-1159

GM1-gangliosidosis in American black bears: clinical, pathological, biochemical and molecular genetic characterization

G(M1)-gangliosidosis is a rare progressive neurodegenerative disorder due to an autosomal recessively inherited deficiency of lysosomal β-galactosidase. We have identified seven American black bears (Ursus americanus) found in the Northeast United States suffering from G(M1)-gangliosidosis. This report describes the clinical features, brain MRI, and morphologic, biochemical and molecular genetic findings in the affected bears. Brain lipids were compared with those in the brain of a G(M1)-mouse. The bears presented at ages 10-14 months in poor clinical condition, lethargic, tremulous and ataxic. They continued to decline and were humanely euthanized. The T(2)-weighted MR images of the brain of one bear disclosed white matter hyperintensity. Morphological studies of the brain from five of the bears revealed enlarged neurons with foamy cytoplasm containing granules. Axonal spheroids were present in white matter. Electron microscopic examination revealed lamellated membrane structures within neurons. Cytoplasmic vacuoles were found in the liver, kidneys and chondrocytes and foamy macrophages within the lungs. Acid β-galactosidase activity in cultured skin fibroblasts was only 1-2% of control values. In the brain, ganglioside-bound sialic acid was increased more than 2-fold with G(M1)-ganglioside predominating. G(A1) content was also increased whereas cerebrosides and sulfatides were markedly decreased. The distribution of gangliosides was similar to that in the G(M1)-mouse brain, but the loss of myelin lipids was greater in the brain of the affected bear than in the brain of the G(M1) mouse. Isolated full-length cDNA of the black bear GLB1 gene revealed 86% homology to its human counterpart in nucleotide sequence and 82% in amino acid sequence. GLB1 cDNA from liver tissue of an affected bear contained a homozygous recessive T(1042) to C transition inducing a Tyr348 to His mutation (Y348H) within a highly conserved region of the GLB1 gene. The coincidence of several black bears with G(M1)-gangliosidosis in the same geographic area suggests increased frequency of a founder mutation in this animal population.

Abstract 1905: Influence of serum and oxygen on lipid biosynthesis and energy metabolism in murine glioblastoma

Glucose and glutamine are essential energy metabolites for brain tumor growth and survival under both normoxic and hypoxic conditions. Carbons derived from either metabolite can be used for lipid synthesis. Here, we used uniformly labeled C14-glucose and C14-glutamine to examine de novo lipid synthesis in the VM-M3 murine glioblastoma cells. The major lipids synthesized included phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylserine (PS), sphingomyelin (SM), phosphatidic acid (PA), cholesterol (Chol), and cardiolipin (CL). De novo lipid synthesis was greater with glucose than with glutamine as the metabolic substrate under normoxia. Conversely, glutamine was the preferred substrate for lipid synthesis under anoxia. Lactate was produced largely from glucose carbons with minimal lactate derived from glutamine. Total lipid synthesis, using either glucose or glutamine, was greater in media without serum than in media containing 10% FBS under normoxia. Significant triglyceride accumulation was observed only under anoxia. Our findings show that lipid biosynthesis using glucose or glutamine is dependent on the type of growth environment, and that the VM-M3 glioblastoma cells can grow under anoxia only through acquisition of lipids, especially cholesterol, from serum. Supported in part from Boston College Res. Expense Fund.

Citation Format: Nathan Ta, Thomas Seyfried. Influence of serum and oxygen on lipid biosynthesis and energy metabolism in murine glioblastoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1905. doi:10.1158/1538-7445.AM2013-1905

Abstract 5429: Robust in vitro cancer metabolism in non-tumorigenic microglial cells

It is well documented that energy metabolism differs between cancerous tissue and normal tissue for a large variety of human and animal tumors. The murine J2 retrovirus contributes to oncogenesis in macrophage cells. The BV-2 microglia cells were immortalized using the v-raf/v-myc carrying J2 retrovirus. These cells, however, do not form tumors when grown in vivo in the natural C57BL/6 host. Consistent with v-raf/v-myc expression, the in vitro metabolic and proliferation rate of the BV-2 cells greatly exceeded that of the tumorigenic and metastatic VM-M3 microglia cells when grown in DMEM containing 25 mM glucose. When controlling for proliferation and ATP production, the BV-2 cells produced more lactate than did the VM-M3 cells under aerobic conditions, thus demonstrating a robust Warburg effect in the BV-2 cells. The Warburg effect is associated with HIF stabilization under aerobic conditions. Mutations in the IDH1 gene produce 2-hydroxyglutarate (2HG), a recognized “onco-metabolite” that also contributes to HIF stabilization under aerobic conditions. Mass spectrometry analysis showed that the non-tumorigenic BV-2 cells made 2-HG only under anoxic conditions. 2-HG was not detected under anoxia or normoxia in VM-M3LM cells, a less malignant clonal variant of VM-M3. It appears that the BV-2 cells have a more robust cancer metabolism than either the high malignant VM-M3 cells or the low malignant VM-M3LM cells. The VM-M3LM cells consumed more oxygen and produced less lactate per ATP than did either the BV-2 cells or the VM-M3 cells, thus displaying a reduced Warburg effect. In other words, the Warburg effect was greatest in the non-tumorigenic BV-2 cells, was lowest in the low malignant VM-M3LM cells, but was intermediate in the high malignant VM-M3 cells. The results suggest that over expression of the v-raf/v-myc oncogenes, production of the IDH1 onco-metabolite, and a robust Warburg effect are not sufficient to drive tumorigenesis in the BV-2 cells. Supported in part from Boston College Res. Expense Fund.

Citation Format: Roberto Flores, Kenjiro Kami, Thomas Seyfried. Robust in vitro cancer metabolism in non-tumorigenic microglial cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5429. doi:10.1158/1538-7445.AM2013-5429

Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.