Increased circulating LDL cholesterol increases myeloma tumour burden in vivo

Gámez B., Morris EV., Olechnowicz S., Sowman, A., Turner, C. and Edwards CM. Multiple myeloma (MM) is a fatal malignancy characterized by an expansion of malignant plasma cells in the bone marrow (BM) and associated with osteolytic bone disease. MM is preceded by the benign condition, monoclonal gammopathy of undetermined significance (MGUS). Understanding MGUS progression and development of MM bone disease is key for patient management. We and others have previously demonstrated that diet-induced obesity promotes myeloma progression, but the mechanisms underlying this remain unknown. The aim of the current study was to determine the effect of dietary cholesterol on MM development. A 2% cholesterol diet was used to increase circulating LDL in mice. Mice were randomly distributed to either a) cholesterol diet 4 weeks prior to 5TGM1 MM inoculation (pretreatment) or b) cholesterol diet 4 weeks prior to MM inoculation and continued for the entire experiment (continuous). Mice on the continuous cholesterol diet had increased tumour burden, associated with an increase in lipid droplet content of MM cells. No differences in tumour burden were seen in those mice where cholesterol diet was halted at time of MM inoculation. In vitro, myeloma cells cultured with delipidated FBS had a 50% reduction in viability after 72 hours. Rich cholesterol content lipoproteins (LDL) but not VLDL could restore MM cell viability, suggesting that cholesterol is responsible for this lipid-depletion effect. Taken together, our results show that high cholesterol promotes myeloma and results in a higher lipid content in myeloma cells, ultimately increasing BM tumour burden. Pretreatment with a cholesterol diet did not alter disease progression suggesting a direct pro-tumourigenic effect of cholesterol. These results demonstrate both the detrimental effect of cholesterol on myeloma progression and the potential for dietary intervention approaches.

The role of biased calcium-sensing receptor signalling in urinary calcium excretion and kidney stone disease

Michelle Goldsworthy1,2, Asha Bayliss2, Anna Gluck2, Akira Wiberg3, Benjamin Turney1, DominicFurniss3, Rajesh Thakker2, Sarah Howles1,2 1Nuffield Department of Surgical Sciences, University of Oxford, United Kingdom.2Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, UnitedKingdom.3Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Universityof Oxford, United Kingdom. Nephrolithiasis is a major health burden with a poorly understood pathogenesis. We conducted a genome-wide association study in British and Japanese populations identifying twenty nephrolithiasis-associated loci. Mutations in the calcium-sensing receptor (CaSR) cause disorders of calcium homeostasis and five identified loci (DGKD, DGKH, WDR72, GPIC1 and BCR) were predicted to influence CaSR-signalling. In a validation population, we demonstrated that genotype at the DGKD-associated locus correlated with urinary calcium excretion but not serum calcium concentration. In vitro studies demonstrated that knockdown and overexpression of DGKD resulted in biased CaSR-signalling. Thus, treatment of CaSR-expressing HEK cells with DGKD-targeted siRNA (DGKD-KD), resulted in decreased MAPK responses to alterations in extracellular calcium concentration [Ca2+]e, as assessed by SRE-reporter and ERK-phosphorylation (pERK) assays, when compared to cells treated with scrambled siRNA (WT) but without alteration in intracellular calcium responses [Ca2+]i as assessed by NFAT-reporter and Fluo-4 calcium assays (SRE maximal response DGKD-KD =5.28 fold change vs. WT=7.20 p=0.0065, pERK maximal response DGKD-KD=24.77, vs. WT= 39.46 fold change, p=0.0056). Conversely, DGKD overexpression (DGKD-OE) increased MAPK responses but suppressed [Ca2+]i responses to alterations in [Ca2+]e (SRE maximal response DGKD-OE =14.13 fold change vs. WT=9.06 fold change, p=0.01; NFAT maximal response DGKD-OE=13.67 fold change vs WT=59.16 fold change, p=0.0001). Our results demonstrate that alterations in DGKD expression cause biased CaSR-signalling. This biased signalling may provide an explanation for the correlation of genotype at the DGKD-associated locus with urinary calcium excretion but not serum calcium concentration. Our findings suggest that biased CaSR-signalling may be a common cause of nephrolithiasis.

Tumor irradiation combined with minimally invasive surgery (vascular-targeted photodynamic therapy) enhances anti-tumour effects in preclinical prostate cancer

Hanna T Sjoberg, Yiannis Philippou, Anette L Magnussen, Iain DC Tullis, Esther Bridges, Andrea Chatrian, Joel Loefebvre, Ka Ho Tam, Emma A Murphy, Jens Rittscher, Dina Preise, Lilach Agemy, Tamar Yechezkel, Sean C Smart, Paul Kinchesh, Stuart Gilchrist, Danny P Allen, David A Scheiblin, Stephen J Lockett, David A Wink, Alastair D Lamb, Ian G Mills, Adrian Harris, Ruth J Muschel, Boris Vojnovic, Avigdor Scherz, Freddie C Hamdy, Richard J Bryant. Introduction There is an important clinical need to improve the treatment of high risk localised and locally advanced prostate cancer (PCa), and to reduce the side effects of these treatments. We hypothesised that multi-modality therapy combining radiotherapy and vascular-targeted photodynamic therapy (VTP) could PCa tumour control compared against monotherapy with each of these treatments alone. This could provide proof-of-concept to take to the clinic. VTP is a minimally invasive focal surgical therapy for localised PCa, which rapidly destroys targeted tumours through vascular disruption. Tumour vasculature is characterised by vessel immaturity, increased permeability, aberrant branching and inefficient flow. Fractionated radiotherapy (FRT) alters the tumour microenvironment and promotes transient vascular normalisation. Materials and Methods We investigated whether sequential delivery of FRT followed by VTP 7 days later improves PCa tumour control compared to monotherapy with FRT or VTP alone. Results FRT induced vascular normalisation changes in PCa flank tumour allografts, improving vascular function as demonstrated using dynamic contrast enhanced magnetic resonance imaging. FRT followed by VTP significantly delayed tumour growth in flank PCa allograft pre-clinical models, compared with monotherapy with FRT or VTP alone, and improved overall survival. Conclusion Taken together, these results suggest that combining FRT and VTP could become a promising multimodal clinical strategy in PCa therapy. This provides proof-of-concept for this multi-modality therapy approach to take forward to early phase clinical trials.

Association of Increased Body Mass Index and Waist to Hip Ratio with Kidney Stone Disease: a prospective analysis of 493,410 UK Biobank participants

Catherine E Lovegrove1,2 – [email protected] Littlejohns3- [email protected] Allen3- [email protected] A Howles1,4- [email protected] W Turney 1,2- [email protected] 1 Department of Urology, Oxford University Hospitals NHS Trust, Oxford, Oxfordshire, UK2 University of Oxford Nuffield Department of Surgical Sciences, Oxford, Oxfordshire, UK3 University of Oxford Nuffield Department of Public Health, Oxford, Oxfordshire, UK4 Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK Objectives To investigate the relationship between measures of adiposity and risk of incident kidney stone disease. Patients and methods The UK Biobank is a prospective cohort study of ~500,000 participants whose height, weight, BMI, waist circumference, hip circumference, waist:hip ratio (WHR), total fat mass, fat-free mass, body-fat percentage and percentage truncal fat were measured at enrolment with linkage to medical records. ICD-10 and OPCS codes were used to identify individuals with a new diagnosis of nephrolithiasis from 2006-2010. Individuals with a history of kidney stones or incomplete data were excluded. Multivariate Cox-proportional hazard models were used to assess associations between anthropometric measures and incident kidney stones. Results From the UK Biobank, 493,410 individuals were identified for inclusion; 3,466 developed a kidney stone during the study period. Increasing weight, BMI, waist and hip circumferences, WHR, and body and truncal fat were associated with increased risk of incident kidney stone disease. However, after adjustment for BMI, only waist circumference and WHR remained significantly associated with risk of nephrolithiasis. In overweight patients, high (men 94-102cm, women 80-88cm) waist circumference or WHR (men >0.9, women >0.85) conferred >40% increased risk of stone formation. Conclusion This study indicates that android fat distribution is independently associated with increased risk of developing nephrolithiasis. Kidney stone disease is known to be associated with hypertension, cardiovascular disease, and diabetes, all of which are linked to android body shape. Our findings provide insight into anthropometric risk factors for stone disease, will facilitate identification of patients at greatest risk of stone recurrence, and will inform prevention strategies.

Increased circulating LDL cholesterol increases myeloma tumour burden in vivo

Gámez B., Morris EV., Olechnowicz S., Sowman, A., Turner, C. and Edwards CM. Multiple myeloma (MM) is a fatal malignancy characterized by an expansion of malignantplasma cells in the bone marrow (BM) and associated with osteolytic bone disease. MM ispreceded by the benign condition, monoclonal gammopathy of undetermined significance(MGUS). Understanding MGUS progression and development of MM bone disease is key forpatient management. We and others have previously demonstrated that diet-induced obesitypromotes myeloma progression, but the mechanisms underlying this remain unknown. The aimof the current study was to determine the effect of dietary cholesterol on MM development. A2% cholesterol diet was used to increase circulating LDL in mice. Mice were randomlydistributed to either a) cholesterol diet 4 weeks prior to 5TGM1 MM inoculation (pretreatment)or b) cholesterol diet 4 weeks prior to MM inoculation and continued for the entire experiment(continuous). Mice on the continuous cholesterol diet had increased tumour burden, associatedwith an increase in lipid droplet content of MM cells. No differences in tumour burden wereseen in those mice where cholesterol diet was halted at time of MM inoculation. In vitro,myeloma cells cultured with delipidated FBS had a 50% reduction in viability after 72 hours. Richcholesterol content lipoproteins (LDL) but not VLDL could restore MM cell viability, suggestingthat cholesterol is responsible for this lipid-depletion effect. Taken together, our results showthat high cholesterol promotes myeloma and results in a higher lipid content in myeloma cells,ultimately increasing BM tumour burden. Pretreatment with a cholesterol diet did not alterdisease progression suggesting a direct pro-tumourigenic effect of cholesterol. These resultsdemonstrate both the detrimental effect of cholesterol on myeloma progression and thepotential for dietary intervention approaches.

Spatial heterogeneity of the immune compartment within the lungs of critical COVID-19 patients

Cross AR, Sansom S, Roberts I, Cerundolo L, Melero I, De Andrea C, Landecho MF, Klenerman P,Hester J, Issa F Acute respiratory distress syndrome (ARDS) is a defining feature of severe infection with theSARS-CoV-2 virus. Approaches to understand the immune response during COVID-19 are largelyconfined to characterisation of circulating leukocytes, however this approach excludes the mostrelevant cells that are active at the site of infection and injury. The aim of this study was to characterise the immune landscape across the lungs of COVID-19patients. Lung samples from three critical COVID-19 patients were assessed for histopathology,viral load, and distribution using qPCR, in situ hybridisation and immunohistochemistry.Leukocyte distribution was then assessed, and the transcript profile of selected areas examinedagainst the >1800 genes in the Cancer Transcriptome Atlas panel on the NanoString GeoMxDigital Spatial Profiling platform. Lung samples exhibited a spectrum of typical COVID-19 pathology with diffuse alveolar damageconsistent with hyaline membrane and type II pneumocyte hyperplasia, interstitialinflammation, organising pneumonia and thrombi. All tissues tested positive for SARS-CoV-2RNA using qPCR, whilst spatially resolved techniques revealed only few and sparsely distributedcells carrying the viral nucleocapsid protein. Multiplexed immunofluorescence for lymphocytes(CD3+) and macrophages (CD68+) was used to select areas of immune enrichment for spatialtranscriptomic profiling. These targeted analyses highlighted functional pathways involved inthe interferon gamma response, TCR activation and antigen presentation. Comparison acrossimmune-enriched areas identified a heterogeneity in lung infiltrates with spatial separation ofchemokine and complement production. Our data identify pathological immune pathways thatare amenable to therapeutic intervention in critical disease.

Development of ex vivo normothermic perfusion as an innovative method to assess pancreases after preservation

Ann Ogbemudia, Julien Branchereau (Joint first authors), Gabriella Hakim, Fungai Dengu, FaysalEl-Gilani, John Mulvey, Kaithlyn Rozenberg, Thomas Prudhomme, Letizia Lo Faro, James Hunter,Paul Johnson, Rutger Ploeg and Peter Friend Objective Static cold storage (SCS) is the standard method for pancreas preservation but does not facilitate objective organ assessment prior to transplantation. Normothermic machine perfusion (NMP) has been used to test other abdominal and thoracic organs’ function and viability in transplantation settings. Our aim was to develop a NMP protocol specific for pancreases and then investigate its potential as an organ assessment strategy. Method 8 porcine pancreases were procured in conditions replicating donation after circulatory death with warm ischaemia time of 25 minutes. After 3 hours of static cold storage (SCS) the pancreases were divided into 3 experimental groups 1) the feasibility group (n=2) that underwent 2.5 hours of NMP 2) the SCS group (n = 2) that underwent an additional 6 hours of SCS prior to assessment on NMP for an hour and 3) the Oxygenated Hypothermic Machine Perfusion (oxyHMP) group (n = 4) that underwent 6 hours of oxyHMP followed by 1-hour assessment on NMP. The NMP protocol used autologous, leucodepleted blood delivered at a mean arterial pressure of 40mmHg with a temperature of 37oC. At timed intervals during NMP, perfusate samples were collected for gas analysis and perfusion parameters were recorded. Results The feasibility group was used to develop the NMP protocol and demonstrated stable perfusion parameters throughout NMP. Compared to the SCS group the oxyHMP group demonstrated better average perfusion characteristics with lower resistances, higher flow rates, lower mean lactate levels and physiological pH. The oxyHMP group maintained normal macroscopic appearances during NMP. At the end of NMP the SCS group had an average 32% weight increase compared to the oxyHMP group that were found to have a 17% weight reduction. Conclusion Normothermic machine perfusion of whole pancreases is feasible after cold preservation and potentially useful as an assessment strategy. Furthermore, it demonstrated that oxygenated HMP may be beneficial for pancreas preservation compared to SCS.

Molecular and proteomic signatures associated with preservation related graft injury: insight from human liver normothermic machine perfusion (NMP)

Fungai Dengu1; Sadr Shaheed1; Letizia Lo Faro1; Adam Thorne1; Honglei Huang1; Peter Friend1,Rutger Ploeg1. 1. Oxford Organ Perfusion Lab, Nuffield Department of Surgical Sciences and Oxford BiomedicalResearch Centre, University of Oxford, Oxford, UK BackgroundContinuous liver NMP is a novel technology associated with safe extension of organ preservation time, increased organ utilisation and reduced early graft injury1. Increasingly, it is utilised as a ‘back to base’ application with cold storage for organ transport and NMP initiated at the implanting centre prior to transplantation2. We aimed to evaluate the impact of additional cold ischaemia time (CIT) on the proteomic and molecular signature of NMP livers. Methods Liver tissue samples (N= 57) from a prospective clinical trial of ‘back to base’ NMP were analysed. Collection occurred at the end of cold storage (LT1), end of NMP/total preservation (LT2) and after organ reperfusion (LT3). Unbiased, label-free-quantitative (LFQ) proteomic analysis was conducted using liquid chromatography with tandem mass spectrometry and trapped ion mobility spectrometry (TIMS) to time-of-flight (TOF) mass analysis (LC-MS/MS TIMS-TOF). Differential expression and Gene Ontology/Pathway analysis were performed. Results LT2 samples with prolonged CIT (>6hr) prior to NMP had significant differential expression of proteins associated with liver-specific oxidative stress, cellular haemostasis and removal of damaged or misfolded proteins (e.g. CYP3A5, PSMB1). LT3 samples, similarly, had reduced proteins involved in autophagy and cell-cycle regulation (e.g. STBD1, CD2AP, GADD45GIP1,) and increased expression of proteins involved in neutrophil chemotaxis, adhesion and aggregation (e.g. S100A9). Discussion The molecular signature of grafts at LT2 and LT3 varies depending on the length of CIT prior to NMP. Further exploration of the molecular signatures associated with preservation related graft injury is required to determine how best to apply this novel technology clinically. References: 1. Nasralla, D. et al. A randomized trial of normothermic preservation in liver transplantation. Nature 557, 50–56 (2018).2. Ceresa, C. D. L. et al. Transient Cold Storage Prior to Normothermic Liver Perfusion May Facilitate Adoption of a Novel Technology. Liver Transplant. lt.25584 (2019).doi:10.1002/lt.25584

Ischaemia reperfusion induces the release of donor derived Passenger Leukocytes (PLs) during normothermic machine perfusion (NMP) of the liver- a new opportunity for ex situ graft leukodepletion?

Fungai Dengu1, Tamsyn Clark1,3, Hussain Abbas1, Etohan Ann Ogbemudia1, Faysal El Gilani1,David Nasralla1, Peter Friend1, James Fildes2 1. Oxford Organ Perfusion Lab, Nuffield Department of Surgical Sciences and Oxford Biomedical ResearchCentre, University of Oxford, Oxford, UK2. The Ex-Vivo Lab, Division of Cell Matrix Biology and Regenerative Medicine, School of BiologicalSciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester AcademicHealth Science Centre, Manchester, UK3. Institute of Biomedical Engineering, University of Oxford, Oxford, UK Background Passenger Leukocytes (PLs) are implicated in both the direct and semi-direct pathways of allorecognition which is the process that underpins acute allograft rejection1. The majority of liver-derived PLs are short lived and predominantly impact early recipient immune responses2. Removal of PLs has been shown in kidney, lung and vascularised composite allografts to reduce early allograft damage and abrogate ejection3. We aimed to assess the use normothermic machine perfusion (NMP) to investigate PL kinetics and explore PL depletion strategies in donor livers. Methods Porcine livers (N=4) procured in a donation after circulatory death (DCD) model were preserved with sequential static cold storage then NMP. During NMP, livers were subjected to repeated 20 min warm ischaemic hits (IH) followed by 30mins of NMP using a leukocyte depleted autologous RBC based perfusate. Leukocytes were quantified using the Sysmex® cell counter system and samples stored for flow cytometric analysis. Results In total, 3.4x106 PLs are effluxed into the circuit immediately after initiation of NMP, this falls rapidly to 1.35x106 by 30 mins. Following the first IH, a further efflux of occurs with a peak of 3.74x106 occurring. The second IH also induced an efflux of cells (1.61x106) with lymphocytes representing the predominant leukocyte sub-type in each efflux. Discussion During NMP, there is an inducible and reproducible efflux of graft derived PLs into the circuit that is composed of predominantly lymphocytes with unexpectedly low numbers of monocytes. Removal of these PLs from the perfusate during NMP may therefore be feasible using an in-line leukocyte-filter. References 1. Alsughayyir, J., Motallebzadeh, R. & Pettigrew, G. J. Are donor lymphocytes a barrier to transplantation tolerance? Curr. Opin. Organ Transplant. 23, 90–96 (2018).2. Mastoridis, S. et al. Impact of donor extracellular vesicle release on recipient cell “cross-dressing” following clinical liver and kidney transplantation. Am. J. Transplant. ajt.16123 (2020). doi:10.1111/ajt.161233. Stone, J. P. et al. Mechanical removal of dendritic cell–generating non-classical monocytes via ex vivo lung perfusion. J. Hear. Lung Transplant. 33, 864–869 (2014).