Janine Krüger

High-Dose Treatment With Telmisartan Induces Monocytic Peroxisome Proliferator-Activated Receptor-γ Target Genes in Patients With the Metabolic Syndrome

The present study aimed to explore the anti-inflammatory effects and peroxisome proliferator-activated receptor-&ggr; (PPAR&ggr;)–activating properties of the angiotensin type 1 receptor blocker telmisartan by analysis of serum interleukin 6 levels and monocytic PPAR&ggr; target gene expression in drug-naïve patients with the metabolic syndrome. This was a 14-week, randomized, double-blind, placebo-controlled 2-center study with telmisartan 80 mg/d and telmisartan 160 mg/d in 54 patients with the metabolic syndrome. In addition to clinical laboratory measurements, peripheral monocytes were extracted by negative isolation using a Dynal Monocyte kit to evaluate ligand-activated PPAR&ggr; target gene expression (CD36 and CD163) at baseline and study end using quantitative real-time RT-PCR. In this low-risk patient population, telmisartan (80 and 160 mg) treatment did not significantly affect serum interleukin 6 levels. Expression of the PPAR&ggr; target gene CD36 in monocytes was markedly induced by telmisartan from baseline to study end (telmisartan 80 mg: 2.3±1.5-fold change versus placebo [P value not significant]; telmisartan 160 mg: 3.5±0.9-fold change versus placebo [P<0.05]). The recently reported PPAR&ggr; target gene CD163 was slightly induced by telmisartan (telmisartan 80 mg: 1.1±0.3-fold change versus placebo [P value not significant]; telmisartan 160 mg: 1.4±0.4-fold change versus placebo [P value not significant]), which did not reach statistical significance. This is the first clinical description of monocytic PPAR&ggr; target gene regulation with high-dose telmisartan treatment. These data implicate that the angiotensin type 1 receptor blocker telmisartan activates PPAR&ggr; in circulating monocytes of patients with the metabolic syndrome.

Development of a telemedical monitoring concept for the care of malnourished geriatric home-dwelling patients: a pilot study.

Elderly patients are at high risk of malnutrition and sarcopenia, promoting further morbidity which in turn decreases quality of life and increases the claiming of medical services and associated costs. Early and sustained administration of oral nutritional supplements has been shown to improve the nutritional status with robust clinical benefit. Many patients however, poorly adhere to prescribed supplements, so consistent monitoring is needed. Clinical monitoring usually ends with the discharge rendering the continuation of nutritional supplement therapy in the patients home problematic. We developed a telemedicine based health care concept for intensive home monitoring. In a first randomized controlled prospective study we analyzed the feasibility of this innovative approach. The intervention group received oral nutritional supplements and telemedical monitoring with daily assessment of body weight, number of taken oral energy supplements and state of health. The control group received usual care. 13 patients were included in each group, eight patients of the intervention group left the study prematurely, five patients were closely monitored and used the devices for a mean 67 ± 63.5 days. Follow up data of body weight and BMI showed no relevant differences between both groups. The results and experiences gained in this pilot study demonstrate that telemedical systems provide encouraging new options to enable an intensive monitoring of malnourished patients. A continuous intensive therapy monitoring of this patient group however, is a particular challenge. Albeit possibilities, limitations and useful parameters were identified, which will be used to improve the conception in an ongoing prospective randomized trial.

Integrin cleavage regulates bidirectional signalling in vascular smooth muscle cells

Integrins link the cytoskeleton to the extracellular matrix, providing outside-in/inside-out signalling essential for vascular smooth muscle cell (VSMC) migration in atherosclerosis. The integrin av subunit is synthesised from its precursor via furin-dependent endoproteolytic cleavage. Furin is a proprotein convertase (PC) highly expressed in VSMCs and in human atherosclerotic lesions. Inhibition of av processing inhibits binding to vitronectin and migration. However, the precise role of furin-dependent av cleavage on integrin bidirectional signalling and subsequent VSMC functions is unknown. Our present study demonstrates that the furin-like PC inhibitor decanoyl-RVKR-chloromethylketone (dec-CMK) inhibited av cleavage. This reduced vitronectin-induced (outside-in) focal adhesion kinase (FAK)- and paxillin-phosphorylation, and VSMC motility. Inside-out-stimulated, integrin- mediated VSMC adhesion/migration relied on integrin-adaptor protein activation following protein kinase C (PKC) and ERK1/2 phosphorylation. In contrast to outside-in signalling, PKC-dependent phosphorylation of FAK and paxillin was unaffected by the status of integrin cleavage. Still, cytoskeleton and focal adhesion site rearrangements were modulated by the inhibition of furin-dependent integrin cleavage, thereby lessening inside-out dependent migration. Hence, we find that integrin bidirectional signalling is critically controlled by furin. Furin- dependent integrin processing modulates rapid adaptive integrin/cytoskeleton changes, essential to VSMC motility, which represents a crucial component in atherosclerosis and restenosis.

Enhanced insulin signaling in density-enhanced phosphatase-1 (DEP-1) knockout mice

Objective Insulin resistance can be triggered by enhanced dephosphorylation of the insulin receptor or downstream components in the insulin signaling cascade through protein tyrosine phosphatases (PTPs). Downregulating density-enhanced phosphatase-1 (DEP-1) resulted in an improved metabolic status in previous analyses. This phenotype was primarily caused by hepatic DEP-1 reduction. Methods Here we further elucidated the role of DEP-1 in glucose homeostasis by employing a conventional knockout model to explore the specific contribution of DEP-1 in metabolic tissues. Ptprj−/− (DEP-1 deficient) and wild-type C57BL/6 mice were fed a low-fat or high-fat diet. Metabolic phenotyping was combined with analyses of phosphorylation patterns of insulin signaling components. Additionally, experiments with skeletal muscle cells and muscle tissue were performed to assess the role of DEP-1 for glucose uptake. Results High-fat diet fed-Ptprj−/− mice displayed enhanced insulin sensitivity and improved glucose tolerance. Furthermore, leptin levels and blood pressure were reduced in Ptprj−/− mice. DEP-1 deficiency resulted in increased phosphorylation of components of the insulin signaling cascade in liver, skeletal muscle and adipose tissue after insulin challenge. The beneficial effect on glucose homeostasis in vivo was corroborated by increased glucose uptake in skeletal muscle cells in which DEP-1 was downregulated, and in skeletal muscle of Ptprj−/− mice. Conclusion Together, these data establish DEP-1 as novel negative regulator of insulin signaling.

Nutrition in Pancreatic Cancer: A Review.

Background: Pancreatic cancer is the fourth leading cause of cancer-related mortality in both genders. More than 80% of patients suffer from significant weight loss at diagnosis and over time develop severe cachexia. Early nutritional support is therefore essential. Summary: This review evaluates the different nutritional therapies, such as enteral nutrition, parenteral nutrition and special nutritional supplements, on nutritional status, quality of life and survival. Key Message: Due to the high prevalence of malnutrition and the rapid development of anorexia-cachexia-syndrome, early nutritional intervention is crucial and supported by clinical data. Practical Implications: Enteral nutrition should be preferred over parenteral nutrition. Omega-3 fatty acids and L-carnitine are promising substances for the prevention of severe cachexia, but further randomized controlled trials are needed to establish generally accepted guidelines on nutrition in pancreatic cancer.

Magnetic Resonance Imaging of Changes in Abdominal Compartments in Obese Diabetics during a Low-Calorie Weight-Loss Program.

Objectives To investigate changes in the fat content of abdominal compartments and muscle area during weight loss using confounder-adjusted chemical-shift-encoded magnetic resonance imaging (MRI) in overweight diabetics. Methods Twenty-nine obese diabetics (10/19 men/women, median age: 59.0 years, median body mass index (BMI): 34.0 kg/m2) prospectively joined a standardized 15-week weight-loss program (six weeks of formula diet exclusively, followed by reintroduction of regular food with gradually increasing energy content over nine weeks) over 15 weeks. All subjects underwent a standardized MRI protocol including a confounder-adjusted chemical-shift-encoded MR sequence with water/fat separation before the program as well at the end of the six weeks of formula diet and at the end of the program at 15 weeks. Fat fractions of abdominal organs and vertebral bone marrow as well as volumes of visceral and subcutaneous fat were determined. Furthermore, muscle area was evaluated using the L4/L5 method. Data were compared using the Wilcoxon signed-rank test for paired samples. Results Median BMI decreased significantly from 34.0 kg/m2 to 29.9 kg/m2 (p < 0.001) at 15 weeks. Liver fat content was normalized (14.2% to 4.1%, p < 0.001) and vertebral bone marrow fat (57.5% to 53.6%, p = 0.018) decreased significantly throughout the program, while fat content of pancreas (9.0%), spleen (0.0%), and psoas muscle (0.0%) did not (p > 0.15). Visceral fat volume (3.2 L to 1.6 L, p < 0.001) and subcutaneous fat diameter (3.0 cm to 2.2 cm, p < 0.001) also decreased significantly. Muscle area declined by 6.8% from 243.9 cm2 to 226.8 cm2. Conclusion MRI allows noninvasive monitoring of changes in abdominal compartments during weight loss. In overweight diabetics, weight loss leads to fat reduction in abdominal compartments, such as visceral fat, as well as liver fat and vertebral bone marrow fat while pancreas fat remains unchanged.

Proprotein Convertase Subtilisin/Kexin Type 3 Promotes Adipose Tissue-Driven Macrophage Chemotaxis and Is Increased in Obesity

Background Matrix metalloproteinase (MMP)-dependent extracellular matrix (ECM) remodeling is a key feature in cardiometabolic syndrome-associated adipogenesis and atherosclerosis. Activation of membrane-tethered (MT) 1-MMP depends on furin (PCSK3). However, the regulation and function of the natural furin-inhibitor serpinB8 and thus furin/MT1-MMP-activity in obesity-related tissue inflammation/remodeling is unknown. Here we aimed to determine the role of serpinB8/furin in obesity-associated chronic inflammation. Methods and Results Monocyte → macrophage transformation was characterized by decreases in serpinB8 and increases in furin/MT1-MMP. Rescue of serpinB8 by protein overexpression inhibited furin-dependent pro-MT1-MMP activation in macrophages, supporting its role as a furin-inhibitor. Obese white adipose tissue-facilitated macrophage migration was inhibited by furin- and MMP-inhibition, stressing the importance of the furin-MMP axis in fat tissue inflammation/remodeling. Monocytes from obese patients (body mass index (BMI) >30kg/m2) had higher furin, MT1-MMP, and resistin gene expression compared to normal weight individuals (BMI<25kg/m2) with significant correlations of BMI/furin and furin/MT1-MMP. In vitro, the adipocytokine resistin induced furin and MT1-MMP in mononuclear cells (MNCs), while MCP-1 had no effect. Conclusions Acquisition of the inflammatory macrophage phenotype is characterized by an imbalance in serpinB8/furin, leading to MT1-MMP activation, thereby enhancing migration. Increases in MT1-MMP and furin are present in MNCs from obese patients. Dissecting the regulation of furin and its inhibitor serpinB8 should facilitate targeting inflammation/remodeling in cardiometabolic diseases.

Knockout of Density-Enhanced Phosphatase-1 Impairs Cerebrovascular Reserve Capacity in an Arteriogenesis Model in Mice

Collateral growth, arteriogenesis, represents a proliferative mechanism involving endothelial cells, smooth muscle cells, and monocytes/macrophages. Here we investigated the role of Density-Enhanced Phosphatase-1 (DEP-1) in arteriogenesis in vivo, a protein-tyrosine-phosphatase that has controversially been discussed with regard to vascular cell biology. Wild-type C57BL/6 mice subjected to permanent left common carotid artery occlusion (CCAO) developed a significant diameter increase in distinct arteries of the circle of Willis, especially in the anterior cerebral artery. Analyzing the impact of loss of DEP-1 function, induction of collateralization was quantified after CCAO and hindlimb femoral artery ligation comparing wild-type and DEP-1−/− mice. Both cerebral collateralization assessed by latex perfusion and peripheral vessel growth in the femoral artery determined by microsphere perfusion and micro-CT analysis were not altered in DEP-1−/− compared to wild-type mice. Cerebrovascular reserve capacity, however, was significantly impaired in DEP-1−/− mice. Cerebrovascular transcriptional analysis of proarteriogenic growth factors and receptors showed specifically reduced transcripts of PDGF-B. SiRNA knockdown of DEP-1 in endothelial cells in vitro also resulted in significant PDGF-B downregulation, providing further evidence for DEP-1 in PDGF-B gene regulation. In summary, our data support the notion of DEP-1 as positive functional regulator in vascular cerebral arteriogenesis, involving differential PDGF-B gene expression.

Inhibition of Src homology 2 domain‐containing phosphatase 1 increases insulin sensitivity in high‐fat diet‐induced insulin‐resistant mice

Insulin resistance plays a crucial role in the development of type 2 diabetes. Insulin receptor signalling is antagonized and tightly controlled by protein tyrosine phosphatases (PTPs). However, the precise role of the PTP src homology 2 domain‐containing phosphatase 1 (SHP‐1) in insulin resistance has not been explored. Male C57BL/6J mice were fed a high‐fat diet (HFD, 60% kcal from fat), to induce insulin resistance, or a low‐fat diet (LFD, 10% kcal from fat) for 10 weeks. Afterwards, HFD‐fed mice were pharmacologically treated with the SHP‐1 (Ptpn6) inhibitor sodium stibogluconate and the broad spectrum pan‐PTP inhibitor bis(maltolato)oxovanadium(IV) (BMOV). Both inhibitors ameliorated the metabolic phenotype, as evidenced by reduced body weight, improved insulin sensitivity and glucose tolerance, which was not due to altered PTP gene expression. In parallel, phosphorylation of the insulin receptor and of the insulin signalling key intermediate Akt was enhanced, and both PTP inhibitors and siRNA‐mediated SHP‐1 downregulation resulted in an increased glucose uptake in vitro. Finally, recombinant SHP‐1 was capable of dephosphorylating the ligand‐induced tyrosine‐phosphorylated insulin receptor. These results indicate a central role of SHP‐1 in insulin signalling during obesity, and SHP‐1 inhibition as a potential therapeutic approach in metabolic diseases.

Early Parenteral Nutrition in Patients with Biliopancreatic Mass Lesions, a Prospective, Randomized Intervention Trial.

Purpose Patients with biliopancreatic tumors frequently suffer from weight loss and cachexia. The in-hospital work-up to differentiate between benign and malignant biliopancreatic lesions requires repeated pre-interventional fasting periods that can aggravate this problem. We conducted a randomized intervention study to test whether routine in-hospital peripheral intravenous nutrition on fasting days (1000 ml/24 h, 700 kcal) has a beneficial effect on body weight and body composition. Material and Methods 168 patients were screened and 100 enrolled in the trial, all undergoing in-hospital work-up for biliopancreatic mass lesions and randomized to either intravenous nutrition or control. Primary endpoint was weight loss at time of hospital discharge; secondary endpoints were parameters determined by bioelectric impedance analysis and quality of life recorded by the EORTC questionnaire. Results Within three months prior to hospital admission patients had a median self-reported loss of 4.0 kg (25*th: -10.0 kg and 75*th* percentile: 0.0kg) of body weight. On a multivariate analysis nutritional intervention increased body weight by 1.7 kg (95% CI: 0.204; 3.210, p = 0.027), particularly in patients with malignant lesions (2.7 kg (95% CI: 0.71; 4.76, p < 0.01). Conclusions In a hospital setting, patients with suspected biliopancreatic mass lesions stabilized their body weight when receiving parenteral nutrition in fasting periods even when no total parenteral nutrition was required. Analysis showed that this effect was greatest in patients with malignant tumors. Further studies will be necessary to see whether patient outcome is affected as well. Trial Registration ClinicalTrials.gov NCT02670265