Compromised intestinal integrity in older adults during daily activities: a pilot study.

BACKGROUND: Malnutrition is a common and significant problem in older adults. Insight into factors underlying malnutrition is needed to develop strategies that can improve the nutritional status. Compromised intestinal integrity caused by gut wall hypoperfusion due to atherosclerosis of the mesenteric arteries in the aging gastrointestinal tract may adversely affect nutrient uptake. The presence of compromised intestinal integrity in older adults is not known. The aim of this study is to provide a proof-of-concept that intestinal integrity is compromised in older adults during daily activities. METHODS: Adults aged ≥75 years living independently without previous gastrointestinal disease or abdominal surgery were asked to complete a standardized walking test and to consume a standardized meal directly afterwards to challenge the mesenteric blood flow. Intestinal fatty acid-binding protein (I-FABP) was measured as a plasma marker of intestinal integrity, in blood samples collected before (baseline) and after the walking test, directly after the meal, and every 15 min thereafter to 75 min postprandially. RESULTS: Thirty-four participants (median age 81 years; 56% female) were included. Of the participants, 18% were malnourished (PG-SGA score ≥ 4), and 32% were at risk of malnutrition (PG-SGA score, 2 or 3). An I-FABP increase of ≥50% from baseline was considered a meaningful loss of intestinal integrity and was observed in 12 participants (35%; 8 females; median age 80 years). No significant differences were observed in either baseline characteristics, walking test scores, or calorie/macronutrient intake between the groups with and without a ≥ 50% I-FABP peak. CONCLUSION: This study is first to indicate that intestinal integrity is compromised during daily activities in a considerable part of older adults living independently.

Evaluating the safety of two human experimental intestinal ischemia reperfusion models: A retrospective observational study.

BACKGROUND: We developed a jejunal and colonic experimental human ischemia-reperfusion (IR) model to study pathophysiological intestinal IR mechanisms and potential new intestinal ischemia biomarkers. Our objective was to evaluate the safety of these IR models by comparing patients undergoing surgery with and without in vivo intestinal IR. METHODS: A retrospective study was performed comparing complication rates and severity, based on the Clavien-Dindo classification system, in patients undergoing pancreatoduodenectomy with (n = 10) and without (n = 20 matched controls) jejunal IR or colorectal surgery with (n = 10) and without (n = 20 matched controls) colon IR. Secondary outcome parameters were operative time, blood loss, 90-day mortality and length of hospital stay. RESULTS: Following pancreatic surgery, 63% of the patients experienced one or more postoperative complications. There was no significant difference in incidence or severity of complications between patients undergoing pancreatic surgery with (70%) or without (60%, P = 0.7) jejunal IR. Following colorectal surgery, 60% of the patients experienced one or more postoperative complication. Complication rate and severity were similar in patients with (50%) and without (65%, P = 0.46) colonic IR. Operative time, amount of blood loss, postoperative C-reactive protein, length of hospital stay or mortality were equal in both intervention and control groups for jejunal and colon IR. CONCLUSION: This study showed that human experimental intestinal IR models are safe in patients undergoing pancreatic or colorectal surgery.

The effects of bariatric surgery on clinical profile, DNA methylation, and ageing in severely obese patients.

BACKGROUND: Severe obesity is a growing, worldwide burden and conventional therapies including radical change of diet and/or increased physical activity have limited results. Bariatric surgery has been proposed as an alternative therapy showing promising results. It leads to substantial weight loss and improvement of comorbidities such as type 2 diabetes. Increased adiposity is associated with changes in epigenetic profile, including DNA methylation. We investigated the effect of bariatric surgery on clinical profile, DNA methylation, and biological age estimated using Horvath's epigenetic clock. RESULTS: To determine the impact of bariatric surgery and subsequent weight loss on clinical traits, a cohort of 40 severely obese individuals (BMI = 30-73 kg/m2) was examined at the time of surgery and at three follow-up visits, i.e., 3, 6, and 12 months after surgery. The majority of the individuals were women (65%) and the mean age at surgery was 45.1 ± 8.1 years. We observed a significant decrease over time in BMI, fasting glucose, HbA1c, HOMA-IR, insulin, total cholesterol, triglycerides, LDL and free fatty acids levels, and a significant small increase in HDL levels (all p values < 0.05). Epigenome-wide association analysis revealed 4857 differentially methylated CpG sites 12 months after surgery (at Bonferroni-corrected p value < 1.09 × 10-7). Including BMI change in the model decreased the number of significantly differentially methylated CpG sites by 51%. Gene set enrichment analysis identified overrepresentation of multiple processes including regulation of transcription, RNA metabolic, and biosynthetic processes in the cell. Bariatric surgery in severely obese patients resulted in a decrease in both biological age and epigenetic age acceleration (EAA) (mean = - 0.92, p value = 0.039). CONCLUSIONS: Our study shows that bariatric surgery leads to substantial BMI decrease and improvement of clinical outcomes observed 12 months after surgery. These changes explained part of the association between bariatric surgery and DNA methylation. We also observed a small, but significant improvement of biological age. These epigenetic changes may be modifiable by environmental lifestyle factors and could be used as potential biomarkers for obesity and in the future for obesity related comorbidities.

Females Are More Resistant to Ischemia-Reperfusion-induced Intestinal Injury Than Males: A Human Study.

BACKGROUND AND OBJECTIVE: Sex differences in responses to intestinal ischemia-reperfusion (IR) have been recognized in animal studies. We aimed to investigate sexual dimorphism in human small intestinal mucosal responses to IR. METHODS: In 16 patients (8 men and 8 women) undergoing pancreaticoduodenectomy, an isolated part of jejunum was subjected to IR. In each patient, intestinal tissue and blood was collected directly after 45 minutes of ischemia without reperfusion (45I-0R), after 30 minutes of reperfusion (45I-30R), and after 120 minutes of reperfusion (45I-120R), as well as a control sample not exposed to IR, to assess epithelial damage, unfolded protein response (UPR) activation, and inflammation. RESULTS: More extensive intestinal epithelial damage was observed in males compared to females. Intestinal fatty acid binding protein (I-FABP) arteriovenous (V-A) concentrations differences were significantly higher in males compared to females at 45I-0R (159.0 [41.0-570.5] ng/mL vs 46.9 [0.3-149.9] ng/mL). Male intestine showed significantly higher levels of UPR activation than female intestine, as well as higher number of apoptotic Paneth cells per crypt at 45I-30R (16.4% [7.1-32.1] vs 10.6% [0.0-25.4]). The inflammatory response in male intestine was significantly higher compared to females, with a higher influx of neutrophils per villus at 45I-30R (4.9 [3.1-12.0] vs 3.3 [0.2-4.5]) and a higher gene expression of TNF-α and IL-10 at 45I-120R. CONCLUSION: The human female small intestine seems less susceptible to IR-induced tissue injury than the male small intestine. Recognition of such differences could lead to the development of novel therapeutic strategies to reduce IR-associated morbidity and mortality.

Histopathology of human small intestinal and colonic ischemia-reperfusion: Experiences from human IR-models.

Intestinal ischemia-reperfusion (IR) injury is a frequent, but potentially life-threatening condition. Although much has been learned about its pathophysiology from animal IR models, the translation to the human setting is imperative for better understanding of its etiology. This could provide us with new insight into development of early detection and potential new therapeutic strategies. Over the past decade, we have studied the pathophysiology of human small intestinal and colonic ischemia-reperfusion (IR) in newly developed human in vivo IR models. In this review, we give an overview of new insights on the sequelae of human intestinal IR, with particular attention for the differences in histopathology between small intestinal and colonic IR.

The effect of Mindfulness-Based Stress Reduction on wound healing: a preliminary study.

Psychological factors have been shown to influence the process of wound healing. This study examined the effect of Mindfulness-Based Stress Reduction (MBSR) on the speed of wound healing. The local production of pro-inflammatory cytokines and growth factors was studied as potential underlying mechanism. Forty-nine adults were randomly allocated to a waiting-list control group (n = 26) or an 8-week MBSR group (n = 23). Pre- and post-intervention/waiting period assessment for both groups consisted of questionnaires. Standardized skin wounds were induced on the forearm using a suction blister method. Primary outcomes were skin permeability and reduction in wound size monitored once a day at day 3, 4, 5, 6, 7, and 10 after injury. Secondary outcomes were cytokines and growth factors and were measured in wound exudates obtained at 3, 6, and 22 h after wounding. Although there was no overall condition effect on skin permeability or wound size, post hoc analyses indicated that larger increases in mindfulness were related to greater reductions in skin permeability 3 and 4 days after wound induction. In addition, MBSR was associated with lower levels of interleukin (IL)-8 and placental growth factor in the wound fluid 22 h after wound induction. These outcomes suggest that increasing mindfulness by MBSR might have beneficial effects on early stages of wound healing. Trial Registration NTR3652, http://www.trialregister.nl.

SM22 a Plasma Biomarker for Human Transmural Intestinal Ischemia.

OBJECTIVE: To evaluate the diagnostic potential of smooth muscle protein of 22 kDa (SM22) as plasma biomarker for the detection of transmural intestinal ischemia. BACKGROUND: Acute mesenteric ischemia is an abdominal emergency requiring rapid diagnosis and treatment. Especially, detection of transmural damage is imperative because it mandates emergency surgery. Since early clinical and radiological signs are nonspecific, there is an urgent need for accurate biomarkers. SM22 is a potential marker for transmural damage because of its abundant expression in intestinal smooth muscles. METHODS: SM22 concentrations were measured using a newly built enzyme-linked immunosorbent assay. SM22 release was assessed in plasma and intestinal tissue of rats subjected to intestinal ischemia. Blood and tissue were sampled at baseline and followed up to 24 hours of ischemia. Next, organ-specific SM22 arteriovenous concentration differences were studied in both rats and patients. Finally, plasma from patients with intestinal ischemia, other acute abdominal complaints, and healthy volunteers were tested for SM22. RESULTS: SM22 concentrations were significantly elevated in rats from 4 hours of ischemia onwards. Furthermore, SM22 plasma concentrations closely paralleled the histological increasing degree of intestinal smooth muscle damage. Arteriovenous calculations showed that SM22 was specifically released by the intestines and renally cleared. First data of SM22 release in man demonstrated that patients with transmural intestinal ischemia had significantly higher plasma SM22 levels than patients with only ischemic mucosal injury, other acute abdominal diseases, or healthy controls. CONCLUSIONS: This study shows that SM22 is released into the circulation upon severe ischemia of the intestinal muscle layers. Plasma levels of SM22 are potentially useful for the detection of transmural intestinal damage.

Plasma cathepsin D correlates with histological classifications of fatty liver disease in adults and responds to intervention.

Non-alcoholic steatohepatitis (NASH) is characterized by liver lipid accumulation and inflammation. The mechanisms that trigger hepatic inflammation are poorly understood and subsequently, no specific non-invasive markers exist. We previously demonstrated a reduction in the plasma lysosomal enzyme, cathepsin D (CatD), in children with NASH compared to children without NASH. Recent studies have raised the concept that non-alcoholic fatty liver disease (NAFLD) in adults is distinct from children due to a different histological pattern in the liver. Yet, the link between plasma CatD to adult NASH was not examined. In the current manuscript, we investigated whether plasma CatD in adults correlates with NASH development and regression. Biopsies were histologically evaluated for inflammation and NAFLD in three complementary cohorts of adults (total n = 248). CatD and alanine aminotransferase (ALT) were measured in plasma. Opposite to our previous observations with childhood NASH, we observed increased levels of plasma CatD in patients with NASH compared to adults without hepatic inflammation. Furthermore, after surgical intervention, we found a reduction of plasma CatD compared to baseline. Our observations highlight a distinct pathophysiology between NASH in children and adults. The observation that plasma CatD correlated with NASH development and regression is promising for NASH diagnosis.

Impact of Duodenal-Jejunal Exclusion on Satiety Hormones.

OBJECTIVE: Bariatric procedures that exclude the proximal small intestine lead to significant weight loss which is probably mediated by changes in hormones that alter appetite, such as peptide YY (PYY), ghrelin, cholecystokinin (CCK), and leptin. Here, the effect of the non-surgical duodenal-jejunal bypass liner (DJBL) on concentrations of hormones implicated in appetite control was investigated. SUBJECTS: A two-center prospective study was conducted between January and December 2010. Seventeen obese subjects with type 2 diabetes were treated with the DJBL for 24 weeks. Fasting concentrations of leptin and meal responses of plasma PYY, CCK, and ghrelin were determined prior to and after implantation of the DJBL. RESULTS: At baseline, subjects had an average body weight of 116.0 ± 5.8 kg. One week after implantation, subjects had lost 4.3 ± 0.6 kg (p < 0.01), which progressed to 12.7 ± 1.3 kg at week 24 (p < 0.01). Postprandial concentrations of PYY and ghrelin increased (baseline vs. week 1 vs. week 24 PYY: 2.6 ± 0.2 vs. 4.1 ± 0.4 vs. 4.1 ± 0.7 nmol/L/min and ghrelin: 7.8 ± 1.8 vs. 11.0 ± 1.8 vs. 10.6 ± 1.8 ng/mL/min, all p < 0.05). In parallel, the CCK response decreased (baseline vs. week 1 vs. week 24: 434 ± 51 vs. 229 ± 52 vs. 256 ± 51 pmol/L/min, p < 0.01). Fasting leptin concentrations also decreased (baseline vs. week 24: 98 ± 17 vs. 53 ± 10 ng/mL, p < 0.01). CONCLUSIONS: DJBL treatment induces weight loss paralleled by changes in concentrations of hormones involved in appetite control.

Evidence for a Cystic Fibrosis Enteropathy.

BACKGROUND: Previous studies have suggested the existence of enteropathy in cystic fibrosis (CF), which may contribute to intestinal function impairment, a poor nutritional status and decline in lung function. This study evaluated enterocyte damage and intestinal inflammation in CF and studied its associations with nutritional status, CF-related morbidities such as impaired lung function and diabetes, and medication use. METHODS: Sixty-eight CF patients and 107 controls were studied. Levels of serum intestinal-fatty acid binding protein (I-FABP), a specific marker for enterocyte damage, were retrospectively determined. The faecal intestinal inflammation marker calprotectin was prospectively studied. Nutritional status, lung function (FEV1), exocrine pancreatic insufficiency (EPI), CF-related diabetes (CFRD) and use of proton pump inhibitors (PPI) were obtained from the medical charts. RESULTS: Serum I-FABP levels were elevated in CF patients as compared with controls (p<0.001), and correlated negatively with FEV1 predicted value in children (r-.734, p<0.05). Faecal calprotectin level was elevated in 93% of CF patients, and correlated negatively with FEV1 predicted value in adults (r-.484, p<0.05). No correlation was found between calprotectin levels in faeces and sputum. Faecal calprotectin level was significantly associated with the presence of CFRD, EPI, and PPI use. CONCLUSION: This study demonstrated enterocyte damage and intestinal inflammation in CF patients, and provides evidence for an inverse correlation between enteropathy and lung function. The presented associations of enteropathy with important CF-related morbidities further emphasize the clinical relevance.

Plasma cholesteryl ester transfer protein is predominantly derived from Kupffer cells.

UNLABELLED: The role of Kupffer cells (KCs) in the pathophysiology of the liver has been firmly established. Nevertheless, KCs have been underexplored as a target for diagnosis and treatment of liver diseases owing to the lack of noninvasive diagnostic tests. We addressed the hypothesis that cholesteryl ester transfer protein (CETP) is mainly derived from KCs and may predict KC content. Microarray analysis of liver and adipose tissue biopsies, obtained from 93 obese subjects who underwent elective bariatric surgery, showed that expression of CETP is markedly higher in liver than adipose tissue. Hepatic expression of CETP correlated strongly with that of KC markers, and CETP messenger RNA and protein colocalized specifically with KCs in human liver sections. Hepatic KC content as well as hepatic CETP expression correlated strongly with plasma CETP concentration. Mechanistic and intervention studies on the role of KCs in determining the plasma CETP concentration were performed in a transgenic (Tg) mouse model expressing human CETP. Selective elimination of KCs from the liver in CETP Tg mice virtually abolished hepatic CETP expression and largely reduced plasma CETP concentration, consequently improving the lipoprotein profile. Conversely, augmentation of KCs after Bacille-Calemette-Guérin vaccination largely increased hepatic CETP expression and plasma CETP. Also, lipid-lowering drugs fenofibrate and niacin reduced liver KC content, accompanied by reduced plasma CETP concentration. CONCLUSIONS: Plasma CETP is predominantly derived from KCs, and plasma CETP level predicts hepatic KC content in humans.

Hepatic Uptake of Rectally Administered Butyrate Prevents an Increase in Systemic Butyrate Concentrations in Humans.

BACKGROUND: Short-chain fatty acids (SCFAs), fermentation products of undigested fibers, are considered beneficial for colonic health. High plasma concentrations are potentially harmful; therefore, information about systemic SCFA clearance is needed before therapeutic use of prebiotics or colonic SCFA administration. OBJECTIVE: The aim of this study was to investigate the effect of rectal butyrate administration on SCFA interorgan exchange. METHODS: Twelve patients (7 men; age: 66.4 ± 2.0 y; BMI 24.5 ± 1.4 kg/m(2)) undergoing upper abdominal surgery participated in this randomized placebo-controlled trial. During surgery, 1 group received a butyrate enema (100 mmol sodium butyrate/L; 60 mL; n = 7), and the other group a placebo (140 mmol 0.9% NaCl/L; 60 mL; n = 5). Before and 5, 15, and 30 min after administration, blood samples were taken from the radial artery, hepatic vein, and portal vein. Plasma SCFA concentrations were analyzed, and fluxes from portal-drained viscera, liver, and splanchnic area were calculated and used for the calculation of the incremental area under the curve (iAUC) over a 30-min period. RESULTS: Rectal butyrate administration led to higher portal butyrate concentrations at 5 min compared with placebo (92.2 ± 27.0 µmol/L vs. 14.3 ± 3.4 µmol/L, respectively; P < 0.01). In the butyrate-treated group, iAUCs of gut release (282.8 ± 133.8 µmol/kg BW · 0.5 h) and liver uptake (-293.7 ± 136.0 µmol/kg BW · 0.5 h) of butyrate were greater than in the placebo group [-16.6 ± 13.4 µmol/kg BW · 0.5 h (gut release) and 16.0 ± 13.8 µmol/kg BW · 0.5 h (liver uptake); P = 0.01 and P < 0.05, respectively]. As a result, splanchnic butyrate release did not differ between groups. CONCLUSION: After colonic butyrate administration, splanchnic butyrate release was prevented in patients undergoing upper abdominal surgery. These observations imply that therapeutic colonic SCFA administration at this dose is safe. The trial was registered at clinicaltrials.gov as NCT02271802.

The Human Colon Is More Resistant to Ischemia-reperfusion-induced Tissue Damage Than the Small Intestine: An Observational Study.

OBJECTIVE: Aim of this study was to draw comparisons between human colonic and jejunal ischemia-reperfusion sequelae in a human in vivo experimental model. BACKGROUND: In patients, colonic ischemia-reperfusion generally has a milder course than small intestinal ischemia-reperfusion. It is unclear which pathophysiologic processes are responsible for this difference. METHODS: In 10 patients undergoing colonic surgery and 10 patients undergoing pancreaticoduodenectomy, 6 cm colon or jejunum was isolated and exposed to 60 minutes ischemia followed by various reperfusion periods. Morphology (hematoxylin and eosin), apoptosis (M30), tight junctions (zonula occludens 1), and neutrophil influx (myeloperoxidase) were assessed using immunohistochemistry. Quantitative polymerase chain reaction and enzyme-linked immunosorbent assay were performed for interleukin-6 and tumor necrosis factor-α. RESULTS: Hematoxylin and eosin staining revealed intact colonic epithelial lining, but extensive damage in jejunal villus tips after 60 minutes ischemia. After reperfusion, the colonic epithelial lining was not affected, whereas the jejunal epithelium was seriously damaged. Colonic apoptosis was limited to scattered cells in surface epithelium, whereas apoptosis was clearly observed in jejunal villi and crypts, (42 times more M30 positivity compared with colon, P < 0.01). Neutrophil influx and increased tumor necrosis factor-α mRNA expression were observed in jejunum after 30 and 120 minutes of reperfusion (P < 0.05). Interleukin-6 mRNA expression was increased in jejunum after 120 minutes of reperfusion (3.6-fold increase, P < 0.05), whereas interleukin-6 protein expression was increased in both colon (1.5-fold increase, P < 0.05) and small intestine (1.5-fold increase, P < 0.05) after 30 and 120 minutes of reperfusion. CONCLUSIONS: Human colon is less susceptible to IR-induced tissue injury than small intestine.

Plasma cathepsin D levels: a novel tool to predict pediatric hepatic inflammation.

OBJECTIVES: Nonalcoholic steatohepatitis (NASH) is the most severe form of a hepatic condition known as nonalcoholic fatty liver disease (NAFLD). NASH is histologically characterized by hepatic fat accumulation, inflammation, and ballooning, and eventually coupled with fibrosis that, in turn, may progress to end-stage liver disease even in young individuals. Hence, there is a critical need for specific noninvasive markers to predict hepatic inflammation at an early age. We investigated whether plasma levels of cathepsin D (CatD), a lysosomal protease, correlated with the severity of liver inflammation in pediatric NAFLD. METHODS: Liver biopsies from children (n=96) with NAFLD were histologically evaluated according to the criteria of Kleiner (NAFLD activity score) and the Brunt's criteria. At the time of liver biopsy, blood was taken and levels of CatD, alanine aminotransferase (ALT), and cytokeratin-18 (CK-18) were measured in plasma. RESULTS: Plasma CatD levels were significantly lower in subjects with liver inflammation compared with steatotic subjects. Furthermore, we found that CatD levels were gradually reduced and corresponded with increasing severity of liver inflammation, steatosis, hepatocellular ballooning, and NAFLD activity score. CatD levels correlated with pediatric NAFLD disease progression better than ALT and CK-18. In particular, CatD showed a high diagnostic accuracy (area under receiver operating characteristic curve (ROC-AUC): 0.94) for the differentiation between steatosis and hepatic inflammation, and reached almost the maximum accuracy (ROC-AUC: 0.998) upon the addition of CK-18. CONCLUSIONS: Plasma CatD holds a high diagnostic value to distinguish pediatric patients with hepatic inflammation from children with steatosis.

The effects of stimulation of the autonomic nervous system via perioperative nutrition on postoperative ileus and anastomotic leakage following colorectal surgery (SANICS II trial): a study protocol for a double-blind randomized controlled trial.

BACKGROUND: Postoperative ileus and anastomotic leakage are important complications following colorectal surgery associated with short-term morbidity and mortality. Previous experimental and preclinical studies have shown that a short intervention with enriched enteral nutrition dampens inflammation via stimulation of the autonomic nervous system and thereby reduces postoperative ileus. Furthermore, early administration of enteral nutrition reduced anastomotic leakage. This study will investigate the effect of nutritional stimulation of the autonomic nervous system just before, during and early after colorectal surgery on inflammation, postoperative ileus and anastomotic leakage. METHODS/DESIGN: This multicenter, prospective, double-blind, randomized controlled trial will include 280 patients undergoing colorectal surgery. All patients will receive a selfmigrating nasojejunal tube that will be connected to a specially designed blinded tubing system. Patients will be allocated either to the intervention group, receiving perioperative nutrition, or to the control group, receiving no nutrition. The primary endpoint is postoperative ileus. Secondary endpoints include anastomotic leakage, local and systemic inflammation, (aspiration) pneumonia, surgical complications classified according to Clavien-Dindo, quality of life, gut barrier integrity and time until functional recovery. Furthermore, a cost-effectiveness analysis will be performed. DISCUSSION: Activation of the autonomic nervous system via perioperative enteral feeding is expected to dampen the local and systemic inflammatory response. Consequently, postoperative ileus will be reduced as well as anastomotic leakage. The present study is the first to investigate the effects of enriched nutrition given shortly before, during and after surgery in a clinical setting. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02175979 - date of registration: 25 June 2014. Dutch Trial Registry: NTR4670 - date of registration: 1 August 2014.

Complement alternative pathway activation in human nonalcoholic steatohepatitis.

The innate immune system plays a major role in the pathogenesis of nonalcoholic steatohepatitis (NASH). Recently we reported complement activation in human NASH. However, it remained unclear whether the alternative pathway of complement, which amplifies C3 activation and which is frequently associated with pathological complement activation leading to disease, was involved. Here, alternative pathway components were investigated in liver biopsies of obese subjects with healthy livers (n = 10) or with NASH (n = 12) using quantitative PCR, Western blotting, and immunofluorescence staining. Properdin accumulated in areas where neutrophils surrounded steatotic hepatocytes, and colocalized with the C3 activation product C3c. C3 activation status as expressed by the C3c/native C3 ratio was 2.6-fold higher (p<0.01) in subjects with NASH despite reduced native C3 concentrations (0.94±0.12 vs. 0.57±0.09; p<0.01). Hepatic properdin levels positively correlated with levels of C3c (rs = 0.69; p<0.05) and C3c/C3 activation ratio (rs = 0.59; p<0.05). C3c, C3 activation status (C3c/C3 ratio) and properdin levels increased with higher lobular inflammation scores as determined according to the Kleiner classification (C3c: p<0.01, C3c/C3 ratio: p<0.05, properdin: p<0.05). Hepatic mRNA expression of factor B and factor D did not differ between subjects with healthy livers and subjects with NASH (factor B: 1.00±0.19 vs. 0.71±0.07, p = 0.26; factor D: 1.00±0.21 vs. 0.66±0.14, p = 0.29;). Hepatic mRNA and protein levels of Decay Accelerating Factor tended to be increased in subjects with NASH (mRNA: 1.00±0.14 vs. 2.37±0.72; p = 0.22; protein: 0.51±0.11 vs. 1.97±0.67; p = 0.28). In contrast, factor H mRNA was downregulated in patients with NASH (1.00±0.09 vs. 0.71±0.06; p<0.05) and a similar trend was observed with hepatic protein levels (1.12±0.16 vs. 0.78±0.07; p = 0.08). Collectively, these data suggest a role for alternative pathway activation in driving hepatic inflammation in NASH. Therefore, alternative pathway factors may be considered attractive targets for treating NASH by inhibiting complement activation.

Protective role of plant sterol and stanol esters in liver inflammation: insights from mice and humans.

The inflammatory component of non-alcoholic steatohepatitis (NASH) can lead to irreversible liver damage. Therefore there is an urgent need to identify novel interventions to combat hepatic inflammation. In mice, omitting cholesterol from the diet reduced hepatic inflammation. Considering the effects of plant sterol/stanol esters on cholesterol metabolism, we hypothesized that plant sterol/stanol esters reduces hepatic inflammation. Indeed, adding plant sterol/stanol esters to a high-fat-diet reduced hepatic inflammation as indicated by immunohistochemical stainings and gene expression for inflammatory markers. Finally, adding sterol/stanol esters lowered hepatic concentrations of cholesterol precursors lathosterol and desmosterol in mice, which were highly elevated in the HFD group similarly as observed in severely obese patients with NASH. In vitro, in isolated LPS stimulated bone marrow derived macrophages desmosterol activated cholesterol efflux whereas sitostanol reduced inflammation. This highly interesting observation that plant sterol/stanol ester consumption leads to complete inhibition of HFD-induced liver inflammation opens new venues in the treatment and prevention of hepatic inflammation.

Hemolysis during cardiac surgery is associated with increased intravascular nitric oxide consumption and perioperative kidney and intestinal tissue damage.

INTRODUCTION: Acute kidney injury (AKI) and intestinal injury negatively impact patient outcome after cardiac surgery. Enhanced nitric oxide (NO) consumption due to intraoperative intravascular hemolysis, may play an important role in this setting. This study investigated the impact of hemolysis on plasma NO consumption, AKI, and intestinal tissue damage, after cardiac surgery. METHODS: Hemolysis (by plasma extracellular (free) hemoglobin; fHb), plasma NO-consumption, plasma fHb-binding capacity by haptoglobin (Hp), renal tubular injury (using urinary N-Acetyl-ß-D-glucosaminidase; NAG), intestinal mucosal injury (through plasma intestinal fatty acid binding protein; IFABP), and AKI were studied in patients undergoing off-pump cardiac surgery (OPCAB, N = 7), on-pump coronary artery bypass grafting (CABG, N = 30), or combined CABG and valve surgery (CABG+Valve, N = 30). RESULTS: FHb plasma levels and NO-consumption significantly increased, while plasma Hp concentrations significantly decreased in CABG and CABG+Valve patients (p < 0.0001) during surgery. The extent of hemolysis and NO-consumption correlated significantly (r (2) = 0.75, p < 0.0001). Also, NAG and IFABP increased in both groups (p < 0.0001, and p < 0.001, respectively), and both were significantly associated with hemolysis (R s = 0.70, p < 0.0001, and R s = 0.26, p = 0.04, respectively) and NO-consumption (Rs = 0.55, p = 0.002, and R s = 0.41, p = 0.03, respectively), also after multivariable logistic regression analysis. OPCAB patients did not show increased fHb, NO-consumption, NAG, or IFABP levels. Patients suffering from AKI (N = 9, 13.4%) displayed significantly higher fHb and NAG levels already during surgery compared to non-AKI patients. CONCLUSIONS: Hemolysis appears to be an important contributor to postoperative kidney injury and intestinal mucosal damage, potentially by limiting NO-bioavailability. This observation offers a novel diagnostic and therapeutic target to improve patient outcome after cardiothoracic surgery.

Proteasome inhibition with bortezomib depletes plasma cells and specific autoantibody production in primary thymic cell cultures from early-onset myasthenia gravis patients.

Bortezomib is a potent inhibitor of proteasomes currently used to eliminate malignant plasma cells in multiple myeloma patients. It is also effective in depleting both alloreactive plasma cells in acute Ab-mediated transplant rejection and their autoreactive counterparts in animal models of lupus and myasthenia gravis (MG). In this study, we demonstrate that bortezomib at 10 nM or higher concentrations killed long-lived plasma cells in cultured thymus cells from nine early-onset MG patients and consistently halted their spontaneous production not only of autoantibodies against the acetylcholine receptor but also of total IgG. Surprisingly, lenalidomide and dexamethasone had little effect on plasma cells. After bortezomib treatment, they showed ultrastructural changes characteristic of endoplasmic reticulum stress after 8 h and were no longer detectable at 24 h. Bortezomib therefore appears promising for treating MG and possibly other Ab-mediated autoimmune or allergic disorders, especially when given in short courses at modest doses before the standard immunosuppressive drugs have taken effect.