An Enriched Environment Enhances Angiogenesis Surrounding the Cingulum in Ischaemic Stroke Rats

An enriched environment (EE) has been demonstrated to improve functional recovery in animal models of ischaemic stroke through enhancing vascular endothelial growth factor- (VEGF-) mediated neuroprotection accompanied by angiogenesis in the ischaemic hemisphere. Whether EEs also promote VEGF-mediated neuroprotection and angiogenesis in the contralateral hemisphere remains unclear. Here, we explored the effect of EEs on VEGF expression and angiogenesis within the contralateral cerebral cortex in a rat middle cerebral artery occlusion/reperfusion (MCAO/r) model. We assessed the expression levels of platelet endothelial cell adhesion molecule-1 (CD31), VEGF, and endothelial nitric oxide synthase (eNOS) in the whole contralateral cerebral cortex using Western blotting assay but did not find an increase in the expression of CD31, VEGF, or eNOS in MCAO/r rats housed in EEs, which suggested that EEs did not enhance the overall expression of VEGF and eNOS or angiogenesis in the entire contralateral cortex. We further analysed the local effect of EEs by immunohistochemistry and found that in and around the bilateral cingulum in MCAO/r rats housed in EEs, haematopoietic progenitor cell antigen- (CD34-) positive endothelial progenitor cells were significantly increased compared with those of rats housed in standard cages (SCs). Further experiments showed that EEs increased neuronal VEGF expression surrounding the cingulum in MCAO/r rats and robustly upregulated eNOS expression. These results revealed that EEs enhanced angiogenesis, VEGF expression, and activation of the VEGF-eNOS pathway in and/or around the cingulum in MCAO/r rats, which were involved in the functional recovery of MCAO/r rats.

EVI1 phosphorylation at S436 regulates interactions with CtBP1 and DNMT3A and promotes self-renewal

The transcriptional regulator EVI1 has an essential role in early development and haematopoiesis. However, acute myeloid leukaemia (AML) driven by aberrantly high EVI1 expression has very poor prognosis. To investigate the effects of post-translational modifications on EVI1 function, we carried out a mass spectrometry (MS) analysis of EVI1 in AML and detected dynamic phosphorylation at serine 436 (S436). Wild-type EVI1 (EVI1-WT) with S436 available for phosphorylation, but not non-phosphorylatable EVI1-S436A, conferred haematopoietic progenitor cell self-renewal and was associated with significantly higher organised transcriptional patterns. In silico modelling of EVI1-S436 phosphorylation showed reduced affinity to CtBP1, and CtBP1 showed reduced interaction with EVI1-WT compared with EVI1-S436A. The motif harbouring S436 is a target of CDK2 and CDK3 kinases, which interacted with EVI1-WT. The methyltransferase DNMT3A bound preferentially to EVI1-WT compared with EVI1-S436A, and a hypomethylated cell population associated by EVI1-WT expression in murine haematopoietic progenitors is not maintained with EVI1-S436A. These data point to EVI1-S436 phosphorylation directing functional protein interactions for haematopoietic self-renewal. Targeting EVI1-S436 phosphorylation may be of therapeutic benefit when treating EVI1-driven leukaemia.

Total Body Irradiation as Conditioning Regimen for Haematopoietic Progenitor Cell Transplant: A Case Report and Literature Review

This case study presents a young adult man with lymphoblastic leukaemia B who required total body irradiation (TBI) as a conditioning regimen for haematopoietic progenitor cell transplant (HPT) as the only curative treatment option for his oncological disease. TBI was carried out with personalised patient immobilisation, three-dimensional simulation, radiophysical planning and dosimetric calculations. A total of 12 Gy were prescribed to be administered twice a day for 3 days in a row by means of volumetric modulated intensity radiotherapy with several isocentres. The best technique for the administration of this radiotherapy is discussed because, although the clinical efficacy of the administration of this body dose has been well known for decades, technological advances have brought us new possibilities when compared to the traditional TBI (bilateral with horizontal photon beam and absorbent screen). These advances include the technique used in this case (multi-isocentre volumetric-radiotherapy), which allows a better doses distribution, reducing the dose in organs at risk (OARs) and producing less toxicity, and therefore allowing the inclusion of patients who would not tolerate a conventional TBI. In addition, this method would allow the dose to be scaled up locally in higher areas at risk with better results in the disease control.

Targeted Molecular Imaging of Translocator Protein (TSPO) Using 18FGE180-PET for the Diagnosis of Gastrointestinal Graft Versus host Disease (GI-GVHD)

Introduction: Acute Gastrointestinal Graft Versus Host Disease (GI-GVHD) is a life-threatening complication following haematopoietic progenitor cell transplantation (HPCT). Recent data suggest that the current gold standard diagnostic test (endoscopic biopsy) fails to identify 26% of those patients requiring treatment. The mitochondrial translocator protein TSPO is upregulated in activated macrophages and inflammatory bowel diseases, and thus may be a biomarker of acute GI-GVHD. 18FGE180 is a novel TSPO-targeting radioligand for use in positron emission tomography imaging (18FGE180-PET). Methods: We performed a prospective observational pilot study evaluating 18FGE180-PET in adults with clinically suspected acute GI-GVHD occurring within 100 days following HPCT. Participants underwent a baseline 18FGE180-PET within 7 days of diagnostic endoscopy, and a follow-up 18FGE180-PET 1-4 weeks later. Tissue avidity was assessed visually in four sections of the gastrointestinal tract (GIT; stomach, duodenum, sigmoid and rectum) and rated by standardised uptake variable (SUV), with "positive" defined by SUV greater than mediastinal blood pool (MBP). Imaging findings were correlated with patient demographics, symptom severity (defined by modified Glucksberg stage), endoscopic findings, and histologic diagnosis. For patients in whom GI-GVHD treatment was initiated (defined as minimum prednisone 1mg/kg or equivalent), the clinical response was correlated with GIT avidity during the second 18FGE180-PET. Results: Six (6) patients were recruited, with median age 57 years (range 53-68 years), at a median 66 days post HPCT (range 26-95 days). Median Glucksberg stage of presumptive GI-GVHD was 2 (range 1-3). The histological diagnosis was GI-GVHD in 4 (66%) patients, and drug toxicity in the remaining two patients. Concordance between histological findings and 18FGE180-PET avidity by GIT section were 50% (stomach), 100% (duodenum), 100% (sigmoid) and 80% (rectum). 18FGE180-PET was highly accurate in duodenum and sigmoid (sensitivity 100%, specificity 100%), moderately accurate in rectum (sensitivity 66%, specificity 100%), and non-specific in stomach (sensitivity 100%, specificity 25%). Five (83%) patients subsequently underwent treatment for GI-GVHD, and of these 4 (80%) underwent repeat 18FGE180-PET for response assessment, seven days after the first. In these patients, high concordance between clinical response and 18FGE180-PET avidity was demonstrated in sigmoid (100%), rectum (100%) and duodenum (75%), compared with poor concordance in stomach (25%). The final patient, whose biopsies were negative for GI-GVHD and did not undergo GVHD treatment, was non-avid at all sites on both initial and subsequent 18FGE180-PET. Conclusion: 18FGE180-PET appears to show utility in the diagnosis of GI-GVHD in small and large bowel. Larger prospective studies, correlating with histological TSPO expression, are warranted. Disclosures No relevant conflicts of interest to declare.

Crohn’s disease patients effectively mobilize peripheral blood stem cells to perform autologous haematopoietic stem cell transplantation

BackgroundTreatment with high doses chemotherapy followed by autologous haematopoietic stem cell transplantation is promising for refractory Crohn’s disease patients with no therapeutic option and at imminent risk of further surgeries.ObjectivesTo evaluate the feasibility and efficacy of haematopoietic progenitor cell mobilization in a group of Crohn’s disease patients preparing for autologous unselected haematopoietic stem cell transplantation in a single institution. This is the first study to evaluate mobilization for Crohn’s disease.MethodsPatients were selected according to criteria of the European Bone Marrow Transplant Society.ResultsAll patients mobilized with the mean number of haematopoietic progenitor cells obtained and infused being 16.17 × 106/CD34+/kg. Most patients required only one leukapheresis session to reach the ideal number of cells. Grafting occurred around ten days after cells infusion. Complications and adverse events during the mobilization period were rare with only one patient presenting sepsis as a relevant event in the period.Most patients 20 (70%) had anaemia from the beginning of the mobilization but only 11 (37.9%) received packed red blood cell transfusions.ConclusionMobilization in patients with Crohn’s disease is effective and it seems they are good mobilizers.