Dose-dependent expression of GFI1 alters metabolism in the haematopoietic progenitors and MLL::AF9-induced leukaemic cells

Growth factor independence 1 (GFI1) is a transcriptional repressor protein that plays an essential role in the differentiation of myeloid and lymphoid progenitors. We and other groups have shown that GFI1 has a dose-dependent role in the initiation, progression, and prognosis of acute myeloid leukaemia (AML) patients by inducing epigenetic changes. We now demonstrate a novel role for dose-dependent GFI1 expression in regulating metabolism in haematopoietic progenitor and leukaemic cells. Using in-vitro and ex-vivo murine models of MLL::AF9-induced human AML and extra-cellular flux assays, we now demonstrate that a lower GFI1 expression enhances oxidative phosphorylation rate via upregulation of the FOXO1- MYC axis. Our findings underscore the significance of therapeutic exploitation in GFI1-low-expressing leukaemia cells by targeting oxidative phosphorylation and glutamine metabolism.

Repinotan, a selective 5-HT1A-R-agonist, antagonizes morphine-induced ventilatory depression in anesthetized rats

BACKGROUND

Spontaneous breathing during mechanical ventilation improves arterial oxygenation and cardiovascular function, but is depressed by opioids during critical care. Opioid-induced ventilatory depression was shown to be counteracted in anesthetized rats by serotonin(1A)-receptor (5-HT(1A)-R)-agonist 8-OH-DPAT, which cannot be applied to humans. Repinotan hydrochloride is a selective 5-HT(1A)-R-agonist already investigated in humans, but the effects on ventilation and nociception are unknown. In this study, we sought to establish (a) the effects of repinotan on spontaneous breathing and nociception, and (b) the interaction with the standard opiate morphine.

METHODS

The dose-dependent effects of repinotan, given alone or in combination with morphine, on spontaneous minute ventilation (MV) and nociceptive tail-flick reflex latencies (TFLs) were measured simultaneously in spontaneously breathing anesthetized rats. An additional series with NaCl 0.9% and the 5-HT(1A)-R-antagonist WAY 100 135 served as controls.

RESULTS

(a) Repinotan dose-dependently activated spontaneous breathing (MV, mean [95% confidence interval]; 53% [29%-77%]) of pretreatment level) and suppressed nociception (TLF, 91% maximum possible effect [68%-114%]) with higher doses of repinotan (2-200 μg/kg). On the contrary, nociception was enhanced with a small dose of repinotan (0.2 μg/kg; TFL, -47% maximum possible effect [-95% to 2%]). Effects were prevented by 5-HT(1A)-antagonist WAY 100 135. (B) Morphine-induced depression of ventilation (MV, -72% [-100% to -44%]) was reversed by repinotan (20 μg/kg), which returned spontaneous ventilation to pretreatment levels (MV, 18% [-40% to 77%]). The morphine-induced complete depression of nociception was sustained throughout repinotan and NaCl 0.9% administration. Despite a mild decrease in mean arterial blood pressure, there were no serious cardiovascular side effects from repinotan.

CONCLUSIONS

The 5-HT(1A)-R-agonist repinotan activates spontaneous breathing in anesthetized rats even in morphine-induced ventilatory depression. The potency of 5-HT(1A)-R-agonists to stimulate spontaneous breathing and their antinociceptive effects should be researched further.

Understanding international differences in terminology for delirium and other types of acute brain dysfunction in critically ill patients

BACKGROUND

Delirium (acute brain dysfunction) is a potentially life threatening disturbance in brain function that frequently occurs in critically ill patients. While this area of brain dysfunction in critical care is rapidly advancing, striking limitations in use of terminology related to delirium internationally are hindering cross-talk and collaborative research. In the English literature, synonyms of delirium such as the Intensive Care Unit syndrome, acute brain dysfunction, acute brain failure, psychosis, confusion, and encephalopathy are widely used. This often leads to scientific "confusion" regarding published data and methodology within studies, which is further exacerbated by organizational, cultural and language barriers.

OBJECTIVE

We undertook this multinational effort to identify conflicts in terminology and phenomenology of delirium to facilitate communication across medical disciplines and languages.

METHODS

The evaluation of the terminology used for acute brain dysfunction was determined conducting communications with 24 authors from academic communities throughout countries/regions that speak the 13 variants of the Romanic languages included into this manuscript.

RESULTS

In the 13 languages utilizing Romanic characters, included in this report, we identified the following terms used to define major types of acute brain dysfunction: coma, delirium, delirio, delirium tremens, délire, confusion mentale, delir, delier, Durchgangs-Syndrom, acute verwardheid, intensiv-psykose, IVA-psykos, IVA-syndrom, akutt konfusion/forvirring. Interestingly two terms are very consistent: 100 % of the selected languages use the term coma or koma to describe patients unresponsive to verbal and/or physical stimuli, and 100% use delirium tremens to define delirium due to alcohol withdrawal. Conversely, only 54% use the term delirium to indicate the disorder as defined by the DSM-IV as an acute change in mental status, inattention, disorganized thinking and altered level of consciousness.

CONCLUSIONS

Attempts towards standardization in terminology, or at least awareness of differences across languages and specialties, will help cross-talk among clinicians and researchers.

Hydrophilic silica aerogels as dermal drug delivery systems--dithranol as a model drug

A special class of porous silica materials, silica aerogels, was recently shown to be a potential candidate for oral drug delivery systems. It was demonstrated, that stability of drugs and their dissolution rate can essentially be improved through the adsorption on to these materials. In this work, drug loaded silica aerogels are firstly applied as dermal drug delivery systems. Dithranol is used as a representative drug since there is a need to enhance its dermal availability. The unstable and nearly water-insoluble drug exhibits a poor penetration. Release of dithranol from aerogels into various semi-solid formulations and its dissolution as well as the release and penetration into artificial membranes were investigated by Fourier-transform infrared attenuated total reflection (FTIR-ATR) spectroscopy. Two model membranes (one hydrophilic and one lipophilic) were applied. Several formulations were tested and the most promising one was used in order to study the penetration of dithranol into human stratum corneum (SC). Dithranol adsorbed on hydrophilic silica aerogels exhibited superior penetration behaviour compared to that of the standard ointment (dithranol in white soft paraffin).

Collagen type XVIII/endostatin is differentially expressed in primary and metastatic colorectal cancers and ovarian carcinomas

Collagen type XVIII (C18) is a nonfibrillar collagen of basement membranes. Its C-terminal fragment, endostatin, has been identified as an inhibitor of angiogenesis. C18 is predominantly expressed by hepatocytes of normal, cirrhotic and neoplastic liver. We compared the patterns of C18 RNA-expression in colonic adenocarcinoma metastases, which represent the most frequently occurring liver tumours, to normal colon mucosa, to primary colon cancers and to ovarian cancers which are often morphologically similar to colonic cancer or metastasis. Two C18-specific RNA-probes were generated to perform in situ hybridization combined with immunohistochemistry for cytokeratin, vimentin and the endothelial marker CD31, in order to characterize the C18-expressing cells. C18/endostatin protein was localized by immunohistology. In colorectal carcinomas and their liver metastases high levels of C18 transcripts were observed in endothelial cells and fibroblasts/myofibroblasts, whereas C18 RNA was virtually absent from carcinoma cells. Ovarian carcinomas displayed high C18 RNA expression both in carcinoma and stromal cells, indicating that induction of C18 transcription in tumour stromal cells is independent of the ability of carcinoma cells to express C18. While the role of tumour cell derived C18 in cancer growth regulation remains unknown, stimulation of proteolysis of the locally strongly expressed C18 to endostatin could offer an attractive approach for a targeted antineoplastic therapy.