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Abstract Lipid and cholesterol metabolism play a crucial role in tumor cell behavior and in shaping the tumor microenvironment. In particular, enzymatic and non-enzymatic cholesterol metabolism, and derived metabolites control dendritic cell (DC) functions, ultimately impacting tumor antigen presentation within and outside the tumor mass, dampening tumor immunity and immunotherapeutic attempts. The mechanisms accounting for such events remain largely to be defined. Here we perturbed (oxy)sterol metabolism genetically and pharmacologically and analyzed the tumor lipidome landscape in relation to the tumor-infiltrating immune cells. We report that perturbing the lipidome of tumor microenvironment by the expression of sulfotransferase 2B1b crucial in cholesterol and oxysterol sulfate synthesis, favored intratumoral representation of monocyte-derived antigen-presenting cells, including monocyte-DCs. We also found that treating mice with a newly developed antagonist of the oxysterol receptors Liver X Receptors (LXRs), promoted intratumoral monocyte-DC differentiation, delayed tumor growth and synergized with anti-PD-1 immunotherapy and adoptive T cell therapy. Of note, looking at LXR/cholesterol gene signature in melanoma patients treated with anti-PD-1-based immunotherapy predicted diverse clinical outcomes. Indeed, patients whose tumors were poorly infiltrated by monocytes/macrophages expressing LXR target genes showed improved survival over the course of therapy. Thus, our data support a role for (oxy)sterol metabolism in shaping monocyte-to-DC differentiation, and in tumor antigen presentation critical for responsiveness to immunotherapy. The identification of a new LXR antagonist opens new treatment avenues for cancer patients.

Joern Pezoldt et al. analyze mouse spleen fibroblasts using single cell RNA sequencing, revealing 11 distinct clusters of fibroblastic cells or subtypes. Their results collectively provide further insight into the transcriptional identities of splenic fibroblasts and innate immune signatures of distinct stromal compartments.

Hepatic metastases are a poor prognostic factor of colorectal carcinoma (CRC) and new strategies to reduce the risk of liver CRC colonization are highly needed. Herein, we used mouse models of hepatic metastatization to demonstrate that the continuous infusion of therapeutic doses of interferon-alpha (IFNα) controls CRC invasion by acting on hepatic endothelial cells (HECs). Mechanistically, IFNα promoted the development of a vascular antimetastatic niche characterized by liver sinusoidal endothelial cells (LSECs) defenestration extracellular matrix and glycocalyx deposition, thus strengthening the liver vascular barrier impairing CRC trans-sinusoidal migration, without requiring a direct action on tumor cells, hepatic stellate cells, hepatocytes, or liver dendritic cells (DCs), Kupffer cells (KCs) and liver capsular macrophages (LCMs). Moreover, IFNα endowed LSECs with efficient cross-priming potential that, along with the early intravascular tumor burden reduction, supported the generation of antitumor CD8+ T cells and ultimately led to the establishment of a protective long-term memory T cell response. These findings provide a rationale for the use of continuous IFNα therapy in perioperative settings to reduce CRC metastatic spreading to the liver.

Introduction: Enkephalins, endogenous opioid peptides, are involved in the regulation of renal function. One derived molecule, proenkephalin A, also known as penKid, has been demonstrated to be a reliable biomarker for kidney function and its plasma concentration correlates with measured glomerular filtration rate. penKid is used for prediction and diagnosis of AKI and need of renal replacement therapy (RRT). penKid has also been used to predict the successful weaning from RRT in patients with AKI. Whether the concentration of penKid is affected or not by RRT is a controversial point and there are no studies describing the kinetics of the molecule in such conditions. The low molecular weight (4.5 kDa) would imply free removal by the glomerulus and the dialysis membranes. During RRT, this reduction could not be detected in clinical practice due to the complex kinetics involving either low dialytic clearance or increased production in response to impaired kidney function. The aim of this study was to determine the sieving coefficient and the diffusive clearance of the penKid molecule in conditions of in vitro continuous veno-venous hemofiltration (CVVH) and continuous veno-venous hemodialysis (CVVHD), respectively, and also the penKid removal ratio in conditions of in vitro hemoadsorption (HA) using a synthetic microporous resin. Methods: Blood spiked with a lyophilized penKid peptide solved in 20 mm dipotassium phosphate and 6 mm disodium EDTA [pH 8] to reach target concentrations is used as testing solution. In each experiment, the blood batch was adjusted at a volume of 1,000 mL, maintained at 37°, and continuously stirred. Samples were collected from blood, ultrafiltrate, and spent dialysate at different times during the experiments. Sieving, clearance, and removal ratio were calculated. Results: Significant removal of penKid was observed in CVVH (sieving 1.04 ± 0.27), in CVVHD (clearance 23.08 ± 0.89), and in HA (removal ratio 76.1 ± 1% after 120 min). Conclusion: penKid is effectively removed by extracorporeal therapies. In presence of anuria, penKid generation kinetics can be calculated based on extracorporeal removal and volume variation. In steady state conditions, declining values may be the result of an initial renal function recovery and may suggest discontinuation and successful liberation from RRT. [ABSTRACT FROM AUTHOR]

Introduction: Per- and polyfluoroalkyl substances (PFAS) are known water pollutants leading to potential public health consequences. High blood levels of PFAS have been associated with several pathological conditions including testicular and kidney cancer. Classic extracorporeal therapies have demonstrated limited efficiency, and new approaches should be explored. In this study, we studied the possible role of hemoadsorption to achieve a fast, safe, and effective removal of PFAS from blood in patients with high blood levels. Methods: We developed an in vitro model of hemoadsorption to test the potential of PFAS removal by extracorporeal treatment. We recirculated a highly polluted batch of water (4 L) through a sorbent cartridge (Jafron Medical, Zhuhai, China) for 120 min at a flow of 150 mL/min. We collected samples at different time points and analyzed 39 different PFAS compounds. Results: For the PFAS compounds with concentrations significantly above normal, we observed a removal ratio close to 90% already within the first 60 min of circulation leading to almost complete elimination of all pollutants at 120 min. Conclusions: The in vitro model of hemoadsorption suggests the possible application in vivo of this technique to reduce/normalize the concentrations of PFAS in patients exposed to water or environmental pollution. [ABSTRACT FROM AUTHOR]

Summary: Lymph nodes (LNs) are secondary lymphoid tissues that play a critical role in filtering the lymph and promoting adaptive immune responses. Surgical resection of LNs, radiation therapy, or infections may damage lymphatic vasculature and compromise immune functions. Here, we describe the generation of functional synthetic lympho-organoids (LOs) using LN stromal progenitors and decellularized extracellular matrix-based scaffolds, two basic constituents of secondary lymphoid tissues. We show that upon transplantation at the site of resected LNs, LOs become integrated into the endogenous lymphatic vasculature and efficiently restore lymphatic drainage and perfusion. Upon immunization, LOs support the activation of antigen-specific immune responses, thus acquiring properties of native lymphoid tissues. These findings provide a proof-of-concept strategy for the development of functional lympho-organoids suitable for restoring lymphatic and immune cell functions. : In this article, Lenti and colleagues show the generation of functional lympho-organoids using basic constituents of the lymph node. Their findings indicate that transplantation of lympho-organoids may represent a therapeutic approach to restore lymphatic and immune cell functions in lymphedema and other diseases in which lymph nodes have been removed or are dysfunctional. Keywords: lymphoid tissue development, stromal cell biology, tissue engineering, preclinical mouse models, tissue regeneration, lymphatic system, lympho-organoids

Abstract Background Milroy‐like disease is the diagnostic definition used for patients with phenotypes that resemble classic Milroy disease (MD) but are negative to genetic testing for FLT4. In this study, we aimed at performing a genetic characterization and biochemical analysis of VEGF‐C variations found in a female proband born with congenital edema consistent with Milroy‐like disease. Methods The proband underwent next‐generation sequencing‐based genetic testing for a panel of genes associated with known forms of hereditary lymphedema. Segregation analysis was performed on family members by direct sequencing. In vitro studies were performed to evaluate the role of a novel identified variant. Results Two VEGF‐C variations were found in the proband, a novel p.(Ser65Arg) and a pathogenic c.148‐3_148‐2delCA, of paternal and maternal origin, respectively. Functional characterization of the p.(Ser65Arg) variation in vitro showed alterations in VEGF‐C processing. Conclusions Our findings reveal an interesting case in which biallelic variants in VEGF‐C are found in a patient with Milroy‐like lymphedema. These data expand our understanding of the etiology of congenital Milroy‐like lymphedema.

Resumo A compressão da artéria subclávia no desfiladeiro torácico é um fenômeno amplamente conhecido. Anormalidades ósseas, como a pseudoartrose da clavícula, podem raramente causar compressão arterial a esse nível. A pseudoartrose pode desenvolver-se em decorrência de um trauma, que é a forma mais comum, ou ser congênita. Os autores descrevem o caso de uma paciente de 44 anos com quadro de isquemia crítica de membro superior direito. Apresentava história de fratura não tratada de clavícula direita aos 9 meses de idade que evoluiu com pseudoartrose e compressão extrínseca com oclusão da artéria subclávia. O segmento da clavicula acometido pela pseudoartrose foi ressecado e realizada uma tromboembolectomia tardia das artérias subclávia, braquial e distais, com boa evolução.

The stromal microenvironment plays a key role in the expansion of chronic lymphocytic leukemia. Here, the authors use the Eµ-TCL1 mouse model to show that leukemic B-cells induce the activation of retinoic acid synthesis in stromal cells of the lymphoid microenvironment, and that impacting on retinoic acid signalling via diet or chemical inhibition prolonged survival by preventing leukemia dissemination and accumulation in lymphoid tissues.

Background: Patients with end-stage kidney disease (ESKD) have altered immunity. Patients on hemodialysis (HD) present a coexistence of immunodeficiency and activation of the immune system. We evaluated the immunophenotypic profile induced by the medium cut-off of Theranova filter during a single HD session in the same individual. Methods: This pilot observational study explored 11 patients (75 ± 8 years and 73% male). Blood samples were collected prior to (predialytic, PRE) and after 4 h (postdialytic, POST) standard HD session with a medium cut-off, polyarylethersulfone and polyvinylpyrrolidone blend, BPA-free membrane. We performed an immunophenotyping characterization by using flow cytometry. We evaluated eryptosis RBCs and HLA-DR expression on monocytes and Treg cells. Results: The percentages of eryptosis in lymphocytes (CD3+), lymphocyte T helper (CD3+ and CD4+) cells, and monocytes (CD45+ and CD14+) were similar pre- and post-HD. On the contrary, HLA-DR expression and Treg cell numbers significantly decreased after HD. Conclusions: Many studies have focused on the comparison between healthy volunteers and HD patients, but very few have focused on the changes that occur after an HD session in the same individual. With this pilot observational study, we have revealed an immunomodulation driven by HD treatment with Theranova filter. Our preliminary results can be considered to be a hypothesis, generating and stimulating further studies with better designs and larger populations. [ABSTRACT FROM AUTHOR]

AKI is associated with increased risk of death, prolonged length of stay and development of de-novo chronic kidney disease. The aim of our study is the development and validation of prediction models to identify the risk of AKI in ICU patients up to 7 days. We retrospectively recruited 692 consecutive patients admitted to the ICU at San Bortolo Hospital (Vicenza, Italy) from 1 June 2016 to 31 March 2017: 455 patients were treated as the derivation group and 237 as the validation group. Candidate variables were selected based on a literature review and expert opinion. Admission eGFR< 90 ml/min /1.73 mq (OR 2.78; 95% CI 1.78-4.35; p

Introduction The mammalian spleen is a secondary lymphoid organ that plays a central role in host defense. As a result, asplenia or hyposplenia and postsplenectomy patients often have an increased [...], The molecular mechanisms that underlie spleen development and congenital asplenia, a condition linked to increased risk of overwhelming infections, remain largely unknown. The transcription factor TLX1 controls cell fate specification and organ expansion during spleen development, and Tlx1 deletion causes asplenia in mice. Deregulation of TLX1 expression has recently been proposed in the pathogenesis of congenital asplenia in patients carrying mutations of the gene-encoding transcription factor SF-1. Herein, we have shown that TLX1-dependent regulation of retinoic acid (RA) metabolism is critical for spleen organogenesis. In a murine model, loss of Tlx1 during formation of the splenic anlage increased RA signaling by regulating several genes involved in RA metabolism. Uncontrolled RA activity resulted in premature differentiation of mesenchymal cells and reduced vasculogenesis of the splenic primordium. Pharmacological inhibition of RA signaling in Tlx1- deficient animals partially rescued the spleen defect. Finally, spleen growth was impaired in mice lacking either cytochrome P450 26B1 (Cyp26b1), which results in excess RA, or retinol dehydrogenase 10 (Rdh10), which results in RA deficiency. Together, these findings establish TLX1 as a critical regulator of RA metabolism and provide mechanistic insights into the molecular determinants of human congenital asplenia.