Glucocorticoid-induced microRNA-511 protects against TNF by down-regulating TNFR1

TNF is a central actor during inflammation and a well-recognized drug target for inflammatory diseases. We found that the mouse strain SPRET/Ei, known for extreme and dominant resistance against TNF-induced shock, displays weak expression of TNF receptor 1 protein (TNFR1) but normal mRNA expression, a trait genetically linked to the major TNFR1 coding gene Tnfrsf1a and to a locus harbouring the predicted TNFR1-regulating miR-511. This miRNA is a genuine TNFR1 regulator in cells. In mice, overexpression of miR-511 down-regulates TNFR1 and protects against TNF, while anti-miR-511 up-regulates TNFR1 and sensitizes for TNF, breaking the resistance of SPRET/Ei. We found that miR-511 inhibits endotoxemia and experimental hepatitis and that this miR is strongly induced by glucocorticoids and is a true TNFR1 modulator and thus an anti-inflammatory miR. Since minimal reductions of TNFR1 have considerable effects on TNF sensitivity, we believe that at least part of the anti-inflammatory effects of glucocorti-coids are mediated by induction of this miR, resulting in reduced TNFR1 expression

Activin is produced by rat Sertoli cells in vitro and can act as an autocrine regulator of Sertoli cell function

Regulation of androgen receptor (AR) mRNA expression was studied in Sertoli cells and peritubular myoid cells isolated from immature rat testis, and in the lymph node carcinoma cell line derived from a human prostate (LNCaP). Addition of dibutyryl-cyclic AMP (dbcAMP) to Sertoli cell cultures resulted in a rapid transient decrease in AR mRNA expression (5 h), which was followed by a gradual increase in AR mRNA expression (24-72 h). This effect of dbcAMP mimicked follicle-stimulating hormone (FSH) action. In peritubular myoid cells, there was only a moderate but prolonged decrease during incubation in the presence of dbcAMP, and in LNCaP cells no effect of dbcAMP on AR mRNA expression was observed. When Sertoli cells or peritubular myoid cells were cultured in the presence of androgens, AR mRNA expression in these cell types did not change. This is in contrast to LNCaP cells, that showed a marked reduction of AR mRNA expression during androgen treatment. In the present experiments, transcriptional regulation of AR gene expression in Sertoli cells and LNCaP cells was also examined. Freshly isolated Sertoli cell clusters were transfected with a series of luciferase reporter gene constructs, driven by the AR promoter. It was found that addition of dbcAMP to the transfected Sertoli cells resulted in a small but consistent increase in reporter gene expression (which was interpreted as resulting from AR promoter activity); a construct that only contained the AR 5' untranslated region of the cDNA sequence did not show such a regulation. The same constructs, transfected into LNCaP cells, did not show any transcriptional down-regulation when the synthetic androgen R1881 was added to the cell cultures. A nuclear transcription elongation experiment (run-on), however, demonstrated that androgen-induced AR mRNA down-regulation in LNCaP cells resulted from an inhibition of AR gene transcription. The present results indicate that in Sertoli cells and LNCaP cells, hormonal effects on AR gene transcription play a role in regulation of AR expression. However, AR gene transcription in these cells is differentially regulated

Decreased expression of ABAT and STC2 hallmarks ER-positive inflammatory breast cancer and endocrine therapy resistance in advanced disease

Background: Patients with Estrogen Receptor α-positive (ER+) Inflammatory Breast Cancer (IBC) are less responsive to endocrine therapy compared with ER+ non-IBC (nIBC) patients. The study of ER+ IBC samples might reveal biomarkers for endocrine resistant breast cancer. Materials & methods: Gene expression profiles of ER+ samples from 201 patients were explored for genes that discriminated between IBC and nIBC. Classifier genes were applied onto clinically annotated expression data from 947 patients with ER+ breast cancer and validated with RT-qPCR for 231 patients treated with first-line tamoxifen. Relationships with metastasis-free survival (MFS) and progression-free survival (PFS) following adjuvant and first-line endocrine treatment, respectively, were investigated using Cox regression analysis. Results: A metagene of six genes including the genes encoding for 4-aminobutyrate aminotransferase (ABAT) and Stanniocalcin-2 (STC2) were identified to distinguish 22 ER+ IBC from 43 ER+ nIBC patients and remained discriminatory in an independent series of 136 patients. The metagene and two genes were not prognostic in 517 (neo)adjuvant untreated lymph node-negative ER+ nIBC breast cancer patients. Only ABAT was related to outcome in 250 patients treated with adjuvant tamoxifen. Three independent series of in total 411 patients with advanced disease showed increased metagene scores and decreased expression of ABAT and STC2 to be correlated with poor first-line endocrine therapy outcome. The biomarkers remained predictive for first-line tamoxifen treatment outcome in multivariate analysis including traditional factors or published signatures. In an exploratory analysis, ABAT and STC2 protein expression levels had no relation with PFS after first-line tamoxifen. Conclusions: This study utilized ER+ IBC to identify a metagene including ABAT and STC2 as predictive biomarkers for endocrine therapy resistance

ECMO for COVID-19 patients in Europe and Israel

Since March 15th, 2020, 177 centres from Europe and Israel have joined the study, routinely reporting on the ECMO support they provide to COVID-19 patients. The mean annual number of cases treated with ECMO in the participating centres before the pandemic (2019) was 55. The number of COVID-19 patients has increased rapidly each week reaching 1531 treated patients as of September 14th. The greatest number of cases has been reported from France (n = 385), UK (n = 193), Germany (n = 176), Spain (n = 166), and Italy (n = 136) .The mean age of treated patients was 52.6 years (range 16–80), 79% were male. The ECMO configuration used was VV in 91% of cases, VA in 5% and other in 4%. The mean PaO2 before ECMO implantation was 65 mmHg. The mean duration of ECMO support thus far has been 18 days and the mean ICU length of stay of these patients was 33 days. As of the 14th September, overall 841 patients have been weaned from ECMO support, 601 died during ECMO support, 71 died after withdrawal of ECMO, 79 are still receiving ECMO support and for 10 patients status n.a. . Our preliminary data suggest that patients placed on ECMO with severe refractory respiratory or cardiac failure secondary to COVID-19 have a reasonable (55%) chance of survival. Further extensive data analysis is expected to provide invaluable information on the demographics, severity of illness, indications and different ECMO management strategies in these patients

Impact of tumor-associated lipogenesis on the composition, properties and functioning of membranes

Doeltreffende behandeling van kanker vereist een goed begrip van de fundamentele verschillen tussen kankercellen en normale cellen en het rationele gebruik van deze kennis voor antineoplastische interventie. Een fundamenteel verschil dat vooral de laatste decennia tot uiting is gekomen is de opmerkelijke activatie van endogene lipogenese in kankercellen. In tegenstelling tot normale cellen die het merendeel van de vereiste lipiden opnemen uit de circulatie, blijken kankercellen hun lipiden vooral de novo aan te maken en worden ze bijgevolg gekenmerkt door een verhoogde expressie van lipogene enzymen. De mechanismen die verantwoordelijk zijn voor deze lipogene verandering worden stelselmatig opgehelderd, maar het belang van deze lipogene omschakeling voor de kankercelbiologie blijft moeilijk te begrijpen en vormt de hoofdvraag van dit thesisproject.In een eerste deel van deze thesis zijn we op zoek gegaan naar een selectieve manier om de tumorgeassocieerde vetzuursynthese te inhiberen om zo de rol van lipogenese beter te kunnen onderzoeken. Soraphen A, een krachtige en zeer selectieve inhibitor van ACC, bleek een doeltreffende component te zijn om de lipogene verandering in prostaatkankercellen om te keren. In een tweede deel hebben we de effecten hiervan nagegaan op de lipidensamenstelling van de cel. Gebruik makend van gemerkte lipidenprecursors en van analytische technieken waaronder TLC, GC en ESI-MS hebben we aangetoond dat het merendeel van de nieuw gesynthetiseerde vetzuren in kankercellen wordt ingebouwd in fosfolipiden (de belangrijkste bouwstenen van cellulaire membranen) en dat inhibitie van vetzuursynthese de cellulaire hoeveelheid fosfolipiden significant vermindert, wat uiteindelijk leidt tot een afname in celvolume en een kleiner membraanoppervlak. Overeenstemmend met het feit dat de de novo vetzuursynthese in zoogdiercellen verzadigde acylketens aanmaakt die niet kunnen omgezet worden naar poly-onverzadigde vetzuren (die daarom uit de voeding moeten opgenomen worden), ging deze afname gepaard met een opmerkelijke daling in verzadigde en mono-onverzadigde acylketens en een stijging in poly-onverzadigde acylketens. In een derde deel hebben we de gevolgen onderzocht van deze opmerkelijke veranderingen voor bepaalde belangrijke eigenschappen van cellulaire membranen. We konden aantonen dat inhibitie van vetzuursynthese leidt tot een verhoogde fluïditeit van het plasmamembraan en beduidende veranderingen veroorzaakt in detergens-resistentie van membranen, overeenstemmend met wijzigingen in membraanmicrostructuur. Verder werden grote veranderingen waargenomen in de enzymatische activiteit van membraangeassocieerde enzymen, zoals het Na/K-ATPase. In een laatste deel van deze thesis hebben we onderzocht of de veranderingen in samenstelling en eigenschappen van membranen potentiële toepassingen hebben voor kankerinterventie. We hebben aangetoond dat inhibitie van tumorgeassocieerde vetzuursynthese de opname van chemotherapeutica zoals doxorubicine verhoogt en hun cytotoxiciteit versterkt.Samenvattend leveren deze gegevens evidentie dat tumorgeassocieerde vetzuursynthese belangrijke effecten heeft op de lipidensamenstelling van kankercellen, de verzadiging van acylketens in cellulaire membranen en de microstructuur en functie van membranen. Inhibitie van tumorgeassocieerde vetzuursynthese keert deze effecten om en heeft mogelijke toepassingen voor chemosensitisatie.nrpages: 136status: publishe