Anterior cruciate ligament reconstruction: Effect of graft tunnel position on early to mid-term clinical outcomes.

BACKGROUND: Patient reported outcome measures (PROMs) can be used to assess knee function following anterior cruciate ligament (ACL) reconstruction. Intra-operatively, femoral and tibial tunnels are created to accommodate the new ACL graft. It is postulated that there is an optimum position and orientation of these tunnels and that outcomes from this procedure are affected by their position. AIM: To evaluate the influence of graft tunnel position on early to mid-term clinical outcomes following ACL reconstruction. METHODS: Six PROMs were collected following ACL reconstruction which included the Knee Injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee, Lysholm, Tegner, EuroQol-5 Dimension-5 level, and Short Form 12-item Health Survey. A total of 8 radiological parameters were measured from post-operative X-rays relating to graft tunnel positions. This data was analysed to assess for any correlations between graft tunnel position and post-operative PROMs. RESULTS: A total of 87 patients were included in the study with a mean post-operative follow-up of 2.3 years (range 1 to 7 years). Posterior position of tibial tunnel was associated with improved KOOS quality of life (rho = 0.43, P = 0.002) and EQ-5D VAS (rho = 0.36, P = 0.010). Anterior position of EndoButton femoral tunnel was associated with an improved EQ-5D index (rho = -0.38, P = 0.028). There were no other significant correlations between any of the other radiological parameters and PROM scores. CONCLUSION: Overall, graft tunnel position had very little correlation with clinical outcomes following ACL reconstruction. A few (posterior) tibial tunnel and (anterior) EndoButton femoral tunnel measurements were associated with better PROMs.

Liver microRNA transcriptome reveals miR-182 as link between type 2 diabetes and fatty liver disease in obesity.

Background: The development of obesity-associated comorbidities such as type 2 diabetes (T2D) and hepatic steatosis has been linked to selected microRNAs in individual studies; however, an unbiased genome-wide approach to map T2D induced changes in the miRNAs landscape in human liver samples, and a subsequent robust identification and validation of target genes are still missing. Methods: Liver biopsies from age- and gender-matched obese individuals with (n=20) or without (n=20) T2D were used for microRNA microarray analysis. The candidate microRNA and target genes were validated in 85 human liver samples, and subsequently mechanistically characterized in hepatic cells as well as by dietary interventions and hepatic overexpression in mice. Results: Here, we present the human hepatic microRNA transcriptome of type 2 diabetes in liver biopsies and use a novel seed prediction tool to robustly identify microRNA target genes, which were then validated in a unique cohort of 85 human livers. Subsequent mouse studies identified a distinct signature of T2D-associated miRNAs, partly conserved in both species. Of those, human-murine miR-182-5 p was the most associated with whole-body glucose homeostasis and hepatic lipid metabolism. Its target gene LRP6 was consistently lower expressed in livers of obese T2D humans and mice as well as under conditions of miR-182-5 p overexpression. Weight loss in obese mice decreased hepatic miR-182-5 p and restored Lrp6 expression and other miR-182-5 p target genes. Hepatic overexpression of miR-182-5 p in mice rapidly decreased LRP6 protein levels and increased liver triglycerides and fasting insulin under obesogenic conditions after only seven days. Conclusions: By mapping the hepatic miRNA-transcriptome of type 2 diabetic obese subjects, validating conserved miRNAs in diet-induced mice, and establishing a novel miRNA prediction tool, we provide a robust and unique resource that will pave the way for future studies in the field. As proof of concept, we revealed that the repression of LRP6 by miR-182-5 p, which promotes lipogenesis and impairs glucose homeostasis, provides a novel mechanistic link between T2D and non-alcoholic fatty liver disease, and demonstrate in vivo that miR-182-5 p can serve as a future drug target for the treatment of obesity-driven hepatic steatosis. Funding: This work was supported by research funding from the Deutsche Forschungsgemeinschaft (KI 1887/2-1, KI 1887/2-2, KI 1887/3-1 and CRC-TR296), the European Research Council (ERC, CoG Yoyo LepReSens no. 101002247; PTP), the Helmholtz Association (Initiative and Networking Fund International Helmholtz Research School for Diabetes; MB) and the German Center for Diabetes Research (DZD Next Grant 82DZD09D1G).

Personalised blood pressure management during major noncardiac surgery and postoperative neurocognitive disorders: a randomised trial.

Background: It remains unknown whether there is a causal relationship between intraoperative hypotension and postoperative neurocognitive disorders. We tested the hypothesis that personalised-compared to routine-intraoperative blood pressure management reduces the incidence of postoperative neurocognitive disorders in patients having major noncardiac surgery. Methods: In this single-centre trial, 328 elective major noncardiac surgery patients were randomly allocated to receive personalised blood pressure management (i.e. maintaining intraoperative mean arterial pressure [MAP] above preoperative baseline MAP from automated 24-h blood pressure monitoring) or routine blood pressure management (i.e. maintaining MAP above 65 mm Hg). The primary outcome was the incidence of neurocognitive disorders (composite of delayed neurocognitive recovery and delirium) between postoperative days 3 and 7. Results: The primary outcome, neurocognitive disorders, occurred in 18 of 147 patients (12%) assigned to personalised and 21 of 148 patients (14%) assigned to routine blood pressure management (odds ratio [OR]=0.84, 95% confidence interval [CI]: 0.40-1.75, P=0.622). Delayed neurocognitive recovery occurred in 17 of 146 patients (12%) assigned to personalised and 17 of 145 patients (12%) assigned to routine blood pressure management (OR=0.99, 95% CI: 0.45-2.17, P=0.983). Delirium occurred in 2 of 157 patients (1%) assigned to personalised and 4 of 158 patients (3%) assigned to routine blood pressure management (OR=0.50, 95% CI: 0.04-3.53, P=0.684). Conclusions: Personalised intraoperative blood pressure management maintaining preoperative baseline MAP neither reduced the incidence of the composite primary outcome neurocognitive disorders between postoperative days 3 and 7 nor the incidences of the components of the composite primary outcome-delayed neurocognitive recovery and delirium-compared to routine blood pressure management in patients having major noncardiac surgery. Clinical trial registration: ClinicalTrials.gov (NCT03442907).

IL-22 promotes liver regeneration after portal vein ligation.

Background: Insufficient remnant liver volume (RLV) after the resection of hepatic malignancy could lead to liver failure and mortality. Portal vein ligation (PVL) prior to hepatectomy is subsequently introduced to increase the remnant liver volume and improve the outcome of hepatic malignancy. IL-22 has previously been reported to promote liver regeneration, while facilitating tumor development in the liver via Steap4 upregulation. Here we performed PVL in mouse models to study the role of IL-22 in liver regeneration post-PVL. Methods: Liver weight and volume was measured via magnetic resonance imaging (MRI). Immunohistochemistry for Ki67 and hepatocyte growth factor (HGF) was performed. IL-22 was analyzed by flow cytometry and quantitative polymerase chain reaction (qPCR) was used for acquisition of Il-33, Steap4, Fga, Fgb and Cebpd. To analyze signaling pathways, mice with deletion of STAT3 and a neutralizing antibody for IL-22 were used. Results: The remnant liver weight and volume increased over time after PVL. Additionally, we found that liver regenerative molecules, including Ki67 and HGF, were significantly increased in remnant liver at day 3 post-PVL, as well as IL-22. Administration of IL-22 neutralizing antibody could reduce Ki67 expression after PVL. The upregulation of IL-22 after PVL was mainly derived from innate cells. IL-22 blockade resulted in lower levels of IL-33 and Steap4 in the remnant liver, which was also the case in mice with deletion of STAT3, the main downstream signaling molecule of IL-22, in hepatocytes. Conclusion: IL-22 promotes liver regeneration after PVL. Thus, a combination of IL-22 supplementation and Steap4 blockade could potentially be applied as a novel therapeutic approach to boost liver regeneration without facilitating tumor progression after PVL.

Obesity and diabetes mellitus are associated with SARS-CoV-2 outcomes without influencing signature genes of extrapulmonary immune compartments at the RNA level.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which is responsible for eliciting Coronavirus disease 2019 (COVID-19) still challenges healthcare services worldwide. While many patients only suffer from mild symptoms, patients with some pre-existing medical conditions are at a higher risk for a detrimental course of disease. However, the underlying mechanisms determining disease course are only partially understood. One key factor influencing disease severity is described to be immune-mediated. In this report, we describe a post-mortem analysis of 45 individuals who died from SARS-CoV-2 infection. We could show that although sociodemographic factors and premedical conditions such as obesity and diabetes mellitus reduced survival time in our cohort, they were not associated with changes in the expression of immune-related signature genes at the RNA level in the blood, the gut, or the liver between these different groups. Our data indicate that obesity and diabetes mellitus influence SARS-CoV-2-related mortality, without influencing the extrapulmonary gene expression of immunity-related signature genes at the RNA level.

Mouse models of spontaneous liver and lung metastasis for colorectal cancer.

To investigate underlying mechanisms for cancer metastasis and promising therapies in animal models, spontaneous metastasis models can be used to recreate metastasis development. Here, we present three mouse models of spontaneous lung and/or liver metastasis induction. We describe steps for cancer cell preparation, mouse analgesia, and three injection techniques (subcutaneous, intracecal, and intramucosal). We then detail procedures for evaluating metastasis. Most of these models generate metastasis in a time span of 4 weeks in the majority of injected mice. For complete details on the use and execution of this protocol, please refer to Giannou et al.1.

IL-10 dampens antitumor immunity and promotes liver metastasis via PD-L1 induction.

BACKGROUND & AIMS: The liver is one of the organs most commonly affected by metastasis. The presence of liver metastases has been reported to be responsible for an immunosuppressive microenvironment and diminished immunotherapy efficacy. Herein, we aimed to investigate the role of IL-10 in liver metastasis and to determine how its modulation could affect the efficacy of immunotherapy in vivo. METHODS: To induce spontaneous or forced liver metastasis in mice, murine cancer cells (MC38) or colon tumor organoids were injected into the cecum or the spleen, respectively. Mice with complete and cell type-specific deletion of IL-10 and IL-10 receptor alpha were used to identify the source and the target of IL-10 during metastasis formation. Programmed death ligand 1 (PD-L1)-deficient mice were used to test the role of this checkpoint. Flow cytometry was applied to characterize the regulation of PD-L1 by IL-10. RESULTS: We found that Il10-deficient mice and mice treated with IL-10 receptor alpha antibodies were protected against liver metastasis formation. Furthermore, by using IL-10 reporter mice, we demonstrated that Foxp3+ regulatory T cells (Tregs) were the major cellular source of IL-10 in liver metastatic sites. Accordingly, deletion of IL-10 in Tregs, but not in myeloid cells, led to reduced liver metastasis. Mechanistically, IL-10 acted on Tregs in an autocrine manner, thereby further amplifying IL-10 production. Furthermore, IL-10 acted on myeloid cells, i.e. monocytes, and induced the upregulation of the immune checkpoint protein PD-L1. Finally, the PD-L1/PD-1 axis attenuated CD8-dependent cytotoxicity against metastatic lesions. CONCLUSIONS: Treg-derived IL-10 upregulates PD-L1 expression in monocytes, which in turn reduces CD8+ T-cell infiltration and related antitumor immunity in the context of colorectal cancer-derived liver metastases. These findings provide the basis for future monitoring and targeting of IL-10 in colorectal cancer-derived liver metastases. IMPACT AND IMPLICATIONS: Liver metastasis diminishes the effectiveness of immunotherapy and increases the mortality rate in patients with colorectal cancer. We investigated the role of IL-10 in liver metastasis formation and assessed its impact on the effectiveness of immunotherapy. Our data show that IL-10 is a pro-metastatic factor involved in liver metastasis formation and that it acts as a regulator of PD-L1. This provides the basis for future monitoring and targeting of IL-10 in colorectal cancer-derived liver metastasis.

Evidence mapping on how to perform an optimal surgical repair of large hiatal hernias.

BACKGROUND: Symptomatic and large hiatal hernia (HH) is a common disorder requiring surgical management. However, there is a lack of systematic, evidence-based recommendations summarizing recent reviews on surgical treatment of symptomatic HH. Therefore, this systematic review aimed to create evidence mapping on the key technical issues of HH repair based on the highest available evidence. METHODS: A systematic review identified studies on eight key issues of large symptomatic HH repair. The literature was screened for the highest level of evidence (LE from level 1 to 5) according to the Oxford Center for evidence-based medicine's scale. For each topic, only studies of the highest available level of evidence were considered. RESULTS: Out of the 28.783 studies matching the keyword algorithm, 47 were considered. The following recommendations could be deduced: minimally invasive surgery is the recommended approach (LE 1a); a complete hernia sac dissection should be considered (LE 3b); extensive division of short gastric vessels cannot be recommended; however, limited dissection of the most upper vessels may be helpful for a floppy fundoplication (LE 1a); vagus nerve should be preserved (LE 3b); a dorso-ventral cruroplasty is recommended (LE 1b); routine fundoplication should be considered to prevent postoperative gastroesophageal reflux (LE 2b); posterior partial fundoplication should be favored over other forms of fundoplication (LE 1a); mesh augmentation is indicated in large HH with paraesophageal involvement (LE 1a). CONCLUSION: The current evidence mapping is a reasonable instrument based on the best evidence available to guide surgeons in determining optimal symptomatic and large HH repair.

CD73-dependent generation of extracellular adenosine by vascular endothelial cells modulates de novo lipogenesis in adipose tissue.

Next to white and brown adipocytes present in white and brown adipose tissue (WAT, BAT), vascular endothelial cells, tissue-resident macrophages and other immune cells have important roles in maintaining adipose tissue homeostasis but also contribute to the etiology of obesity-associated chronic inflammatory metabolic diseases. In addition to hormonal signals such as insulin and norepinephrine, extracellular adenine nucleotides modulate lipid storage, fatty acid release and thermogenic responses in adipose tissues. The complex regulation of extracellular adenine nucleotides involves a network of ectoenzymes that convert ATP via ADP and AMP to adenosine. However, in WAT and BAT the processing of extracellular adenine nucleotides and its relevance for intercellular communications are still largely unknown. Based on our observations that in adipose tissues the adenosine-generating enzyme CD73 is mainly expressed by vascular endothelial cells, we studied glucose and lipid handling, energy expenditure and adaptive thermogenesis in mice lacking endothelial CD73 housed at different ambient temperatures. Under conditions of thermogenic activation, CD73 expressed by endothelial cells is dispensable for the expression of thermogenic genes as well as energy expenditure. Notably, thermoneutral housing leading to a state of low energy expenditure and lipid accumulation in adipose tissues resulted in enhanced glucose uptake into WAT of endothelial CD73-deficient mice. This effect was associated with elevated expression levels of de novo lipogenesis genes. Mechanistic studies provide evidence that extracellular adenosine is imported into adipocytes and converted to AMP by adenosine kinase. Subsequently, activation of the AMP kinase lowers the expression of de novo lipogenesis genes, most likely via inactivation of the transcription factor carbohydrate response element binding protein (ChREBP). In conclusion, this study demonstrates that endothelial-derived extracellular adenosine generated via the ectoenzyme CD73 is a paracrine factor shaping lipid metabolism in WAT.