Obesity and its influence on liver dysfunction, morbidity and mortality after liver resection.

Background: Obesity and associated steatosis is an increasing health problem worldwide. Its influence on post-hepatectomy liver failure (PHLF) and after liver resection (LR) is still unclear. Methods: Patients who underwent LR were investigated and divided into three groups [normal weight: body mass index (BMI) 18.5-24.9 kg/m2, overweight: BMI 25.0-29.9 kg/m2, obese: BMI ≥30 kg/m2] in this retrospective study. Primary aim of this study was to assess the influence of BMI and nonalcoholic steatohepatitis (NASH) on PHLF and morbidity. Results: Of 888 included patients, 361 (40.7%) had normal weight, 360 (40.5%) were overweight, 167 (18.8%) were obese. Median age was 62.5 years (IQR, 54-69 years). The primary indication for LR was colorectal liver metastases (CLM) (n=366, 41.2%). NASH was present in 58 (16.1%) of normal weight, 84 (23.3%) of overweight and 69 (41.3%) of obese patients (P<0.001). PHLF occurred in 16.3% in normal weight, 15.3% in overweight and 11.4% in obese patients (P=0.32). NASH was not associated with PHLF. There was no association between patients' weight and the occurrence of postoperative complications (P=0.45). At multivariable analysis, solely major LR [odds ratio (OR): 2.7, 95% confidence interval (CI): 1.83-4.04; P<0.001] remained a significant predictor for PHLF. Conclusions: Postoperative complications and PHLF are comparable in normal weight, overweight and obese patients and LRs using modern techniques can be safely performed in these patients.

Duodenal macrophages control dietary iron absorption via local degradation of transferrin.

Iron is an essential cellular metal that is important for many physiological functions including erythropoiesis and host defense. It is absorbed from the diet in the duodenum and loaded onto transferrin (Tf), the main iron transport protein. Inefficient dietary iron uptake promotes many diseases, but mechanisms regulating iron absorption remain poorly understood. By assessing mice that harbor a macrophage-specific deletion of the tuberous sclerosis complex 2 (Tsc2), a negative regulator of mechanistic target of rapamycin complex 1 (mTORC1), we found that these mice possessed various defects in iron metabolism, including defective steady-state erythropoiesis and a reduced saturation of Tf with iron. This iron deficiency phenotype was associated with an iron import block from the duodenal epithelial cells into the circulation. Activation of mTORC1 in villous duodenal CD68+ macrophages induced serine protease expression and promoted local degradation of Tf, whereas the depletion of macrophages in mice increased Tf levels. Inhibition of mTORC1 with everolimus or serine protease activity with nafamostat restored Tf levels and Tf saturation in the Tsc2-deficient mice. Physiologically, Tf levels were regulated in the duodenum during the prandial process and Citrobacter rodentium infection. These data suggest that duodenal macrophages determine iron transfer to the circulation by controlling Tf availability in the lamina propria villi.

Mimicking Tumor Cell Heterogeneity of Colorectal Cancer in a Patient-derived Organoid-Fibroblast Model.

BACKGROUND & AIMS: Patient-derived organoid cancer models are generated from epithelial tumor cells and reflect tumor characteristics. However, they lack the complexity of the tumor microenvironment, which is a key driver of tumorigenesis and therapy response. Here, we developed a colorectal cancer organoid model that incorporates matched epithelial cells and stromal fibroblasts. METHODS: Primary fibroblasts and tumor cells were isolated from colorectal cancer specimens. Fibroblasts were characterized for their proteome, secretome, and gene expression signatures. Fibroblast/organoid co-cultures were analyzed by immunohistochemistry and compared with their tissue of origin, as well as on gene expression levels compared with standard organoid models. Bioinformatics deconvolution was used to calculate cellular proportions of cell subsets in organoids based on single-cell RNA sequencing data. RESULTS: Normal primary fibroblasts, isolated from tumor adjacent tissue, and cancer associated fibroblasts retained their molecular characteristics in vitro, including higher motility of cancer associated compared with normal fibroblasts. Importantly, both cancer-associated fibroblasts and normal fibroblasts supported cancer cell proliferation in 3D co-cultures, without the addition of classical niche factors. Organoids grown together with fibroblasts displayed a larger cellular heterogeneity of tumor cells compared with mono-cultures and closely resembled the in vivo tumor morphology. Additionally, we observed a mutual crosstalk between tumor cells and fibroblasts in the co-cultures. This was manifested by considerably deregulated pathways such as cell-cell communication and extracellular matrix remodeling in the organoids. Thrombospondin-1 was identified as a critical factor for fibroblast invasiveness. CONCLUSION: We developed a physiological tumor/stroma model, which will be vital as a personalized tumor model to study disease mechanisms and therapy response in colorectal cancer.

LY6G6D is a selectively expressed colorectal cancer antigen that can be used for targeting a therapeutic T-cell response by a T-cell engager.

Colorectal cancer (CRC) is one of the most common cancers worldwide and demands more effective treatments. We sought to identify tumor selective CRC antigens and their therapeutic potential for cytotoxic T-cell targeting by transcriptomic and immunohistochemical analysis. LY6G6D was identified as a tumor selectively expressed CRC antigen, mainly in the microsatellite stable (MSS) subtype. A specific anti LY6G6D/CD3 T cell engager (TcE) was generated and demonstrated potent tumor cell killing and T cell activation in vitro. Ex vivo treatment of primary patient-derived CRC tumor slice cultures with the LY6G6D/CD3 TcE led to IFNγ secretion in LY6G6D positive tumor samples. In vivo, LY6G6D/CD3 TcE monotherapy demonstrated tumor regressions in pre-clinical mouse models of engrafted human CRC tumor cells and PBMCs. Lastly, 2D and 3D cocultures of LY6G6D positive and negative cells were used to explore the bystander killing of LY6G6D negative cells after specific activation of T cells by LY6G6D positive cells. LY6G6D/CD3 TcE treatment was shown to lyse target negative cells in the vicinity of target positive cells through a combined effect of IFNγ, TNFα and Fas/FasL. In summary, LY6G6D was identified as a selectively expressed CRC antigen that can be utilized to potently re-direct and activate cytotoxic T-cells to lyse LY6G6D expressing CRC using a TcE. This effect can be spread to target negative neighboring tumor cells, potentially leading to improved therapeutic efficacy.

A Novel B7-H6-Targeted IgG-Like T Cell-Engaging Antibody for the Treatment of Gastrointestinal Tumors.

PURPOSE: Advanced-stage gastrointestinal cancers represent a high unmet need requiring new effective therapies. We investigated the antitumor activity of a novel T cell-engaging antibody (B7-H6/CD3 ITE) targeting B7-H6, a tumor-associated antigen that is expressed in gastrointestinal tumors. EXPERIMENTAL DESIGN: Membrane proteomics and IHC analysis identified B7-H6 as a tumor-associated antigen in gastrointestinal tumor tissues with no to very little expression in normal tissues. The antitumor activity and mode of action of B7-H6/CD3 ITE was evaluated in in vitro coculture assays, in humanized mouse tumor models, and in colorectal cancer precision cut tumor slice cultures. RESULTS: B7-H6 expression was detected in 98% of colorectal cancer, 77% of gastric cancer, and 63% of pancreatic cancer tissue samples. B7-H6/CD3 ITE-mediated redirection of T cells toward B7-H6-positive tumor cells resulted in B7-H6-dependent lysis of tumor cells, activation and proliferation of T cells, and cytokine secretion in in vitro coculture assays, and infiltration of T cells into tumor tissues associated with tumor regression in in vivo colorectal cancer models. In primary patient-derived colorectal cancer precision-cut tumor slice cultures, treatment with B7-H6/CD3 ITE elicited cytokine secretion by endogenous tumor-infiltrating immune cells. Combination with anti-PD-1 further enhanced the activity of the B7-H6/CD3 ITE. CONCLUSION: These data highlight the potential of the B7-H6/CD3 ITE to induce T cell-redirected lysis of tumor cells and recruitment of T cells into noninflamed tumor tissues, leading to antitumor activity in in vitro, in vivo, and human tumor slice cultures, which supports further evaluation in a clinical study.

Awareness of obstetricians for long-term risks in women with a history of preeclampsia or HELLP syndrome.

PURPOSE: Hypertensive disorders of pregnancy are still a leading cause of maternal and neonatal morbidity and mortality worldwide. Women with a history of preeclampsia have an increased risk for future cardiovascular and cerebrovascular disease, renal disease as well as diabetes mellitus. There is little knowledge on postpartum risk management. The aim of this study was to assess follow-up care for patients after pre-eclampsia or HELLP syndrome. METHODS: This questionnaire-based cross-sectional study aimed to evaluate the current recommendations of obstetricians in Austria regarding follow-up care, long-term risk counselling and risk of recurrence in future pregnancies after preeclampsia or HELLP syndrome. Data were collected using a survey, based on recommendations given by three substantial guidelines on hypertensive disorders of pregnancy, which was distributed via e-mail to 69 public obstetric departments in Austria. Each obstetric department was required to answer one questionnaire per local protocol. RESULTS: Our results revealed that of the 48 participating hospitals most obstetricians are aware of the importance of follow-up care for women after a pregnancy complicated by preeclampsia. Our data show that most physicians counselled patients about the future cardiovascular health risks associated with preeclampsia or HELLP syndrome (79.2%). Most obstetricians recommended lifestyle modification (77.1%) and continued blood pressure measurements (97.9%). All centers stated to counsel about the risk of recurrence (100%). However, counselling regarding follow-up care to exclude kidney damage (37.5%) and underlying diseases like thrombophilia (39.6%) were less prioritized. CONCLUSIONS: We were able to show that counselling concerning the risk of long-term cardiovascular disease and risk of recurrence after a pregnancy complicated by preeclampsia or HELLP syndrome has been established in obstetric departments in public hospitals. Regarding the evaluation of underlying chronic diseases such as thrombophilia or renal disease, as well as counselling on the future risk of renal disease is still improvable according to our data. Further evaluation of follow-up care after hypertensive disorders of pregnancy in the outpatient and private sector and implementation of structured guidelines for follow-up, as well as screening for cardiovascular disease are necessary to ensure adequate risk management and to provide opportunities for prevention.

WAT-on-a-chip integrating human mature white adipocytes for mechanistic research and pharmaceutical applications.

Obesity and its numerous adverse health consequences have taken on global, pandemic proportions. White adipose tissue (WAT) - a key contributor in many metabolic diseases - contributes about one fourth of a healthy human's body mass. Despite its significance, many WAT-related pathophysiogical mechanisms in humans are still not understood, largely due to the reliance on non-human animal models. In recent years, Organ-on-a-chip (OoC) platforms have developed into promising alternatives for animal models; these systems integrate engineered human tissues into physiological microenvironment supplied by a vasculature-like microfluidic perfusion. Here, we report the development of a novel OoC that integrates functional mature human white adipocytes. The WAT-on-a-chip is a multilayer device that features tissue chambers tailored specifically for the maintenance of 3D tissues based on human primary adipocytes, with supporting nourishment provided through perfused media channels. The platform's capability to maintain long-term viability and functionality of white adipocytes was confirmed by real-time monitoring of fatty acid uptake, by quantification of metabolite release into the effluent media as well as by an intact responsiveness to a therapeutic compound. The novel system provides a promising tool for wide-ranging applications in mechanistic research of WAT-related biology, in studying of pathophysiological mechanisms in obesity and diabetes, and in R&D of pharmaceutical industry.