Cathelicidin Antimicrobial Peptide Levels in Atherosclerosis and Myocardial Infarction in Mice and Human.

Obesity represents a worldwide health challenge, and the condition is accompanied by elevated risk of cardiovascular diseases caused by metabolic dysfunction and proinflammatory adipokines. Among those, the immune-modulatory cathelicidin antimicrobial peptide (human: CAMP; murine: CRAMP) might contribute to the interaction of the innate immune system and metabolism in these settings. We investigated systemic CAMP/CRAMP levels in experimental murine models of atherosclerosis, myocardial infarction and cardiovascular patients. Atherosclerosis was induced in low-density lipoprotein receptor-deficient (Ldlr-/-) mice by high-fat diet (HFD). C57BL/6J wild-type mice were subjected to myocardial infarction by permanent or transient left anterior descending (LAD)-ligation. Cramp gene expression in murine organs and tissues was investigated via real-time PCR. Blood samples of 234 adult individuals with or without coronary artery disease (CAD) were collected. Human and murine CAMP/CRAMP serum levels were quantified by ELISA. Atherosclerotic mice exhibited significantly increased CRAMP serum levels and induced Cramp gene expression in the spleen and liver, whereas experimental myocardial infarction substantially decreased CRAMP serum levels. Human CAMP serum quantities were not significantly affected by CAD while being correlated with leukocytes and pro-inflammatory cytokines. Our data show an influence of cathelicidin in experimental atherosclerosis, myocardial infarction, as well as in patients with CAD. Further studies are needed to elucidate the pathophysiological mechanism.

Regulation of Cathelicidin Antimicrobial Peptide (CAMP) Gene Expression by TNFα and cfDNA in Adipocytes.

Understanding the complex interactions between metabolism and the immune system ("metaflammation") is crucial for the identification of key immunomodulatory factors as potential therapeutic targets in obesity and in cardiovascular diseases. Cathelicidin antimicrobial peptide (CAMP) is an important factor of innate immunity and is expressed in adipocytes. CAMP, therefore, might play a role as an adipokine in metaflammation and adipose inflammation. TNFα, cell-free nucleic acids (cfDNA), and toll-like receptor (TLR) 9 are components of the innate immune system and are functionally active in adipose tissue. The aim of the present study was to investigate the impact of TNFα and cfDNA on CAMP expression in adipocytes. Since cfDNA acts as a physiological TLR9 agonist, we additionally investigated TLR9-mediated CAMP regulation in adipocytes and adipose tissue. CAMP gene expression in murine 3T3-L1 and human SGBS adipocytes and in murine and human adipose tissues was quantified by real-time PCR. Adipocyte inflammation was induced in vitro by TNFα and cfDNA stimulation. Serum CAMP concentrations in TLR9 knockout (KO) and in wildtype mice were quantified by ELISA. In primary adipocytes of wildtype and TLR9 KO mice, CAMP gene expression was quantified by real-time PCR. CAMP gene expression was considerably increased in 3T3-L1 and SGBS adipocytes during differentiation. TNFα significantly induced CAMP gene expression in mature adipocytes, which was effectively antagonized by inhibition of PI3K signaling. Cell-free nucleic acids (cfDNA) significantly impaired CAMP gene expression, whereas synthetic agonistic and antagonistic TLR9 ligands had no effect. CAMP and TLR9 gene expression were correlated positively in murine and human subcutaneous but not in intra-abdominal/visceral adipose tissues. Male TLR9 knockout mice exhibited lower systemic CAMP concentrations than wildtype mice. CAMP gene expression levels in primary adipocytes did not significantly differ between wildtype and TLR9 KO mice. These findings suggest a regulatory role of inflammatory mediators, such as TNFα and cfDNA, in adipocytic CAMP expression as a novel putative molecular mechanism in adipose tissue innate immunity.

Circulating Concentrations of Cathelicidin Anti-Microbial Peptide (CAMP) Are Increased during Oral Glucose Tolerance Test.

Recent investigation has revealed the significant role of Cathelicidin antimicrobial peptide (CAMP) in infection defense and innate immunity processes in adipose tissue. Meanwhile, knowledge of its regulation and functions in metabolic contexts as an adipokine remains sparce. The present study investigated the postprandial regulation of circulating CAMP levels during oral glucose tolerance tests (OGTTs). Eighty-six metabolically healthy volunteers participated in a standardized 75 g-2 h-OGTT setting. The effects of exogenous glucose, insulin, and incretins on CAMP expression in human adipocyte culture (cell-line SGBS) were studied in vitro. CAMP concentrations in blood serum samples were measured by ELISA techniques and adipocyte gene expression levels were quantified by real-time PCR. Of note, base-line CAMP serum quantities were negatively correlated with HDL cholesterol levels as well as with the anti-inflammatory adipokine adiponectin. During the 2 h following glucose ingestion, a significant rise in circulating CAMP concentrations was observed in considerable contrast to reduced quantities of fatty acid binding proteins (FABP) 2 and 4 and dipeptidyl peptidase 4 (DPP4). In SGBS adipocytes, neither differing glucose levels nor insulin or incretin treatment significantly induced CAMP mRNA levels. According to our data, glucose represents a positive postprandial regulator of systemic CAMP. This effect apparently is not mediated by the regulatory impact of glucose metabolism on adipocyte CAMP expression.

The emerging role of bile acids in white adipose tissue.

The effects of bile acids (BAs) on liver, enteroendocrine function, small intestine, and brown adipose tissue have been described extensively. Outside the liver, BAs in the peripheral circulation system represent a specific but underappreciated physiological compartment. We discuss how systemic BAs can be regarded as specific steroidal hormones that act on white adipocytes, and suggest the name 'bilokines' ('bile hormones') for the specific FXR/TGR5 receptor interaction in adipocytes. Some BAs and their agonists regulate adipocyte differentiation, lipid accumulation, hypoxia, autophagy, adipokine and cytokine secretion, insulin signaling, and glucose uptake. BA signaling could provide a new therapeutic avenue for adipoflammation and metaflammation in visceral obesity, the causal mechanisms underlying insulin resistance and type 2 diabetes mellitus (T2D).

Circulating Levels of Cathelicidin Antimicrobial Peptide (CAMP) Are Affected by Oral Lipid Ingestion.

INTRODUCTION: Obesity and related diseases are among the main public health issues in the western world. They are thought to be caused by a state of chronic, low-grade inflammation. Cathelicidin antimicrobial peptide (CAMP) was recently discovered to be expressed and secreted by adipocytes. Representing a novel immunomodulatory adipokine, CAMP might play an important role in the complex interaction between metabolism and inflammation. METHODS: In a cohort of 80 volunteers, serum samples were collected prior to, and 2 h, 4 h, and 6 h after, oral lipid ingestion. CAMP, fatty acid binding proteins 2 and 4 (FABP-2/-4), and dipeptidylpeptidase-4 (DPP-4) serum concentrations were measured via ELISA. Human Simpson-Golabi-Behmel syndrome (SGBS) adipocytes were treated with free fatty acids, and gene expression levels of CAMP, FABP-4, and DPP-4 were quantified by RT-PCR. RESULTS: The mean base-line CAMP serum concentration was 55.78 ± 29.26 ng/mL, with a range of 10.77-146.24 ng/mL. Interestingly, CAMP serum levels were positively correlated with LDL cholesterol, but negatively correlated with HDL cholesterol and adiponectin. Men exhibited higher CAMP serum concentrations than women, an effect apparently linked to oral contraception in the majority of female participants. In both genders, CAMP serum concentrations significantly decreased in a stepwise manner 4 h and 6 h after oral lipid ingestion. This decline was paralleled by a rise of serum bile acid and triglyceride levels upon lipid ingestion. In human SGBS adipocytes, treatment with free fatty acids did not affect CAMP gene expression, but increased FABP-4 gene expression. CONCLUSIONS: In conclusion, systemic levels of the antimicrobial peptide and novel adipokine CAMP are significantly decreased upon oral lipid ingestion. While this decline might be linked to the simultaneous increase in bile acids, the underlying mechanisms remain to be elucidated. Furthermore, CAMP might indicate a putative novel cardiovascular biomarker of both inflammatory and metabolic relevance in metaflammation and adipose inflammation.

[Whipple's triad with high and low insulin levels]. / Whipple-Trias mit erhöhten und erniedrigten Insulinspiegeln.

A 69-year-old female patient and a 70-year-old male patient were admitted to hospital with recurrent, severe hypoglycemic episodes and a typical manifestation of Whipple's triad. In the female, elevated levels of insulin, C­peptide and pro-insulin together with pathological findings during a fasting test proved the presence of an insulinoma, which could be detected by Ga-68-DOTATOC-PET-CT in the pancreas. There was a very rare co-existence of a neuroendocrine Merkel cell carcinoma. In the male, levels of insulin and C­peptide were suppressed and a diagnosis of paraneoplastic hypoglycemia by IGF­2 secretion was made with increased glucose disposal in skeletal muscle proven by 18F­FDG-PET-CT.

Serum Chemerin Is Decreased by Roux-en-Y Gastric Bypass and Low Calorie-Formula Diet in Obese Individuals.

The pleiotropic chemokine chemerin is involved in multiple processes in metabolism and inflammation. The present study aimed to elucidate its regulation in morbid obesity and during therapy-induced rapid weight loss. A total of 128 severely obese patients were enrolled, and their basal anthropometric and clinical parameters were assessed. In total, 64 individuals attended a conservative 12-month weight loss program that included a low calorie-formula diet (LCD), and 64 patients underwent bariatric surgery (Roux-en-Y gastric bypass, RYGB). Blood serum was obtained at study baseline and at follow-up visits after 3, 6, and 12 months. Systemic chemerin concentrations, as well as metabolic and immunological parameters, were quantified. During the 12-month period studied, serum chemerin levels decreased significantly with weight loss after bariatric surgery, as well as with conservative low calorie therapy; however, the effects of RYGB were generally stronger. No substantial associations of systemic chemerin concentrations with therapy-induced improvement of type 2 diabetes and with indicators of liver function and fibrosis were observed. We conclude that systemic chemerin levels decrease in obese individuals during weight loss, regardless of the therapeutic strategy. A potential involvement in weight loss-associated improvement of metabolic disorders and liver fibrosis remains to be further investigated.

Neurometabolic Dysfunction in SPG11 Hereditary Spastic Paraplegia.

BACKGROUND: Pathogenic variants in SPG11 cause the most common autosomal recessive complicated hereditary spastic paraplegia. Besides the prototypical combination of spastic paraplegia with a thin corpus callosum, obesity has increasingly been reported in this multisystem neurodegenerative disease. However, a detailed analysis of the metabolic state is lacking. METHODS: In order to characterize metabolic alterations, a cross-sectional analysis was performed comparing SPG11 patients (n = 16) and matched healthy controls (n = 16). We quantified anthropometric parameters, body composition as determined by bioimpedance spectroscopy, and serum metabolic biomarkers, and we measured hypothalamic volume by high-field MRI. RESULTS: Compared to healthy controls, SPG11 patients exhibited profound changes in body composition, characterized by increased fat tissue index, decreased lean tissue index, and decreased muscle mass. The presence of lymphedema correlated with increased extracellular fluid. The serum levels of the adipokines leptin, resistin, and progranulin were significantly altered in SPG11 while adiponectin and C1q/TNF-related protein 3 (CTRP-3) were unchanged. MRI volumetry revealed a decreased hypothalamic volume in SPG11 patients. CONCLUSIONS: Body composition, adipokine levels, and hypothalamic volume are altered in SPG11. Our data indicate a link between obesity and hypothalamic neurodegeneration in SPG11 and imply that specific metabolic interventions may prevent obesity despite severely impaired mobility in SPG11.

Circulating Adipokines and Hepatokines Serve as Diagnostic Markers during Obesity Therapy.

Allocation of morbidly obese patients to either conservative therapy options-such as lifestyle intervention and/or low-calorie diet (LCD)-or to bariatric surgery-preferably sleeve gastrectomy or Roux-en-Y gastric bypass (RYGB)-represents a crucial decision in order to obtain sustainable metabolic improvement and weight loss. The present study encompasses 160 severely obese patients, 81 of whom participated in an LCD program, whereas 79 underwent RYGB surgery. The post-interventional dynamics of physiologically relevant adipokines and hepatokines (ANGPTL4, CCL5, GDF15, GPNMB, IGFBP6), as well as their correlation with fat mass reduction and improvement of liver fibrosis, were analyzed. Systemic GDF15 was characterized as an excellent predictive marker for hepatic fibrosis as well as type 2 diabetes mellitus. Of note, baseline GDF15 serum concentrations were positively correlated with NFS and HbA1c levels after correction for BMI, suggesting GDF15 as a BMI-independent marker of hepatic fibrosis and T2D in obese individuals. Specific GDF15 cut-off values for both diseases were calculated. Overall, the present data demonstrate that circulating levels of specific adipokines and hepatokines are regulated with therapy-induced fat loss and metabolic improvement and might, therefore, serve as biomarkers for the success of obesity therapy strategies.

Toll-like Receptor 7 (TLR7) Is Expressed in Adipocytes and the Pharmacological TLR7 Agonist Imiquimod and Adipocyte-Derived Cell-Free Nucleic Acids (cfDNA) Regulate Adipocyte Function.

Endosome-localized Toll-like receptors (TLRs) 3 and 9 are expressed and functionally active in adipocytes. The functionality and role of TLR7 in adipocyte biology and innate immunity of adipose tissue (AT) is poorly characterized. We analyzed TLR7 mRNA and protein expression in murine 3T3-L1 and primary adipocytes, in co-cultures of 3T3-L1 adipocytes with murine J774A.1 monocytes and in human AT. The effects of TLR7 agonists imiquimod (IMQ) and cell-free nucleic acids (cfDNA) on adipokine concentration in cell-culture supernatants and gene expression profile were investigated. We found that TLR7 expression is strongly induced during adipocyte differentiation. TLR7 gene expression in adipocytes and AT stroma-vascular cells (SVC) seems to be independent of TLR9. IMQ downregulates resistin concentration in adipocyte cell-culture supernatants and modulates gene expression of glucose transporter Glut4. Adipocyte-derived cfDNA reduces adiponectin and resistin in cell-culture supernatants and potentially inhibits Glut4 gene expression. The responsiveness of 3T3-L1 adipocytes to imiquimod is preserved in co-culture with J774A.1 monocytes. Obesity-related, adipocyte-derived cfDNA engages adipocytic pattern recognition receptors (PRRs), modulating AT immune and metabolic homeostasis during adipose inflammation.

Improvement of Type 2 Diabetes Mellitus and Attenuation of NAFLD Are Associated with the Success of Obesity Therapy.

Obesity and type 2 diabetes mellitus (T2D) represent important comorbidities of the metabolic syndrome, which are associated with non-alcoholic fatty liver disease (NAFLD)-related hepatic fibrosis. In total, 160 morbidly obese patients-81 following a low-calorie formula diet (LCD) program and 79 undergoing bariatric surgery (Roux-en-Y gastric bypass, RYGB)-were examined for anthropometric and metabolic parameters at base-line and during 12 months of weight loss, focusing on a putative co-regulation of T2D parameters and liver fibrosis risk. High NAFLD fibrosis scores (NFS) before intervention were associated with elevated HbA1c levels and T2D. Loss of weight and body fat percentage (BFL) were associated with improved glucose and lipid metabolism and reduced risk of NAFLD-related fibrosis, with particularly beneficial effects by RYGB. Both T2D improvement and NFS decrease were positively associated with high BFL. A highly significant correlation of NFS reduction with BFL was restricted to male patients while being absent in females, accompanied by generally higher BFL in men. Overall, the data display the relation of BFL, T2D improvement, and reduced NAFLD-related fibrosis risk during weight loss in morbidly obese individuals induced by diet or RYGB. Furthermore, our data suggest a considerable sexual dimorphism concerning the correlation of fat loss and improved risk of liver fibrosis.

Impact of oral lipid and glucose tolerance tests on the postprandial concentrations of angiopoietin-like proteins (Angptl) 3 and 4.

BACKGROUND: The postprandial regulation of angiopoietin-like proteins (Angptls) and their expression in adipocytes is poorly characterized. OBJECTIVE: Circulating Angptl3 and 4 were analyzed in healthy individuals undergoing either an oral lipid tolerance test (OLTT; n = 98) or an oral glucose tolerance test (OGTT; n = 99). Venous blood was drawn after 0, 2, 4, and 6 h during OLTT and after 0, 1, and 2 h during OGTT. Anthropometric and laboratory parameters were assessed and concentrations of Angptls were quantified by enzyme-linked immunosorbent assay. Angptl gene expression in 3T3-L1 adipocytes and in murine adipose tissues and cellular fractions was analyzed by quantitative real-time PCR. RESULTS: Angptl3 concentrations significantly decreased while Angptl4 levels continuously increased during OLTT. Both proteins remained unaffected during OGTT. Angptl3 and Angptl4 were expressed in murine subcutaneous and visceral AT with higher mRNA levels in mature adipocytes when compared to the stroma-vascular cell fraction. Both proteins were strongly induced during 3T3-L1 adipocyte differentiation and they were unresponsive to glucose in mature fat cells. Adipocyte Angptl3 (but not Angptl4) mRNA expression was inhibited by the polyunsaturated fatty acids arachidonic acid and docosahexaenoic acid, whereas nine types of dietary fatty acids remained without any effect. CONCLUSIONS: There is evidence of short-time regulation of Angptl3/4 levels upon metabolic stress. Angptl4 expression is high and Angptl3 expression is low in AT and restricted mainly to mature adipocytes without any differences concerning fat compartments. Whereas dietary fatty acids and glucose are without any effect, omega-3/-6-polyunsaturated fatty acids inhibited Anptl3 expression in adipocytes.

Meteorin-Like Protein (Metrnl) in Obesity, during Weight Loss and in Adipocyte Differentiation.

Meteorin-like protein (Metrnl) is an adipo-myokine with pleiotropic effects in adipose tissue (AT). Its systemic regulation in obesity and under weight loss is unclear. Circulating Metrnl concentrations were analyzed by ELISA in severely obese patients undergoing bariatric surgery (BS) or low calorie diet (LCD). Metrnl mRNA expression was analyzed in human and murine tissues and cell lines by quantitative real-time PCR. About 312 morbidly obese individuals underwent BS (n = 181; BMI 53.4 + 6.8 kg/m2) or LCD (n = 131; BMI 43.5 + 6.7 kg/m2). Serum samples were obtained at baseline and 3, 6, and 12 months after intervention. AT specimen from subcutaneous and visceral adipose tissue were resected during BS. Serum Metrnl levels were lower in type 2 diabetic patients and negatively correlated with HbA1c. In BS and LCD patients, Metrnl concentrations significantly increased after 3 months and returned to baseline levels after 12 months. There was no gender-specific effect. Metrnl mRNA expression did not differ between visceral and subcutaneous AT in n = 130 patients. In contrast, Metrnl gene expression in mice was highest in intra-abdominal AT followed by subcutaneous, peri-renal, and brown AT. In the murine 3T3-L1 cell line, Metrnl expression was high in pre-adipocytes and mature adipocytes with a transient downregulation during adipocyte differentiation. Metrnl expression remained unaffected upon treatment with glucose, insulin, fatty acids, bile acids, and incretins. Polyunsaturated omega-3 and omega-6 fatty acids downregulated Metrnl expression. Systemic Metrnl is transiently upregulated during massive weight loss and gene expression in adipocytes is differentially regulated.

Anti-Inflammatory Effects of C1q/Tumor Necrosis Factor-Related Protein 3 (CTRP3) in Endothelial Cells.

The C1q/TNF-related protein 3 (CTRP3) represents a pleiotropic adipokine reciprocally associated with obesity and type 2 diabetes mellitus and exhibits anti-inflammatory properties in relation to lipopolysaccharides (LPS)-mediated effects in adipocytes, as well as monocytes/macrophages. Here, we focused on the influence of CTRP3 on LPS-mediated effects in endothelial cells in order to expand the understanding of a possible anti-inflammatory function of CTRP3 in a setting of endotoxemia. An organ- and tissue-specific expression analysis by real-time PCR revealed a considerable Ctrp3 expression in various adipose tissue compartments; however, higher levels were detected in the aorta and in abundantly perfused tissues (bone marrow and the thyroid gland). We observed a robust Ctrp3 expression in primary endothelial cells and a transient upregulation in murine endothelial (MyEND) cells by LPS (50 ng/mL). In MyEND cells, CTRP3 inhibited the LPS-induced expression of interleukin (Il)-6 and the tumor necrosis factor (Tnf)-α, and suppressed the LPS-dependent expression of the major endothelial adhesion molecules Vcam-1 and Icam-1. The LPS-induced adhesion of monocytic cells to an endothelial monolayer was antagonized by CTRP3. In C57BL/6J mice with an LPS-induced systemic inflammation, exogenous CTRP3 did not affect circulating levels of TNF-α, ICAM-1, and VCAM-1. In conclusion, we characterized CTRP3 beyond its function as an adipokine in a setting of vascular inflammation. CTRP3 inhibited LPS-induced endothelial expression of adhesion molecules and monocyte cell adhesion, indicating an important vascular anti-inflammatory role for CTRP3 in endotoxemia.

Evidence of a Muscle-Brain Axis by Quantification of the Neurotrophic Myokine METRNL (Meteorin-Like Protein) in Human Cerebrospinal Fluid and Serum.

Data on the quantification of the potentially neurotrophic adipo-myokine METRNL (Meteorin-like protein) in human cerebrospinal fluid (CSF) are lacking and migration of this secreted protein across the blood-brain barrier (BBB) is uncertain. In the present pilot study, METRNL concentrations were quantified by ELISA in paired serum and CSF samples of 260 patients (107 males, 153 females) undergoing neurological evaluation. METRNL was abundant in serum (801.2 ± 378.3 pg/mL) and CSF (1007.2 ± 624.2 pg/mL) with a CSF/serum ratio of 1.4 ± 0.8. Serum METRNL levels were significantly correlated (rho = +0.521) to those in CSF. CSF METRNL concentrations were significantly correlated (rho = +0.480) with albumin CSF/serum ratios. The CSF/serum ratios of METRNL and albumin were positively correlated in Reibergram analysis (rho = 0.498), indicating that raising CSF concentrations of METRNL are mediated by increasing BBB dysfunction. The CSF concentrations of METRNL strongly increased in a stepwise manner along with increasing BBB dysfunction from grade 0 to grade 3 and with rising CSF cell count. CSF/serum ratio of METRNL also increased from grade 0 (1.2 ± 0.7) to grade 3 (3.0 ± 0.2). Furthermore, CSF levels were positively correlated with age. In conclusion, METRNL is a secreted and neurotrophic myokine that crosses over the BBB. CSF concentrations of METRNL increase with BBB dysfunction.

The adipokine C1q/TNF-related protein-3 (CTRP-3) inhibits Toll-like receptor (TLR)-induced expression of Cathelicidin antimicrobial peptide (CAMP) in adipocytes.

BACKGROUND AND AIM: CAMP (Cathelicidin antimicrobial peptide) expression in adipocytes is regulated by Toll-like receptor (TLR) agonists. Secreted adipokines such as CTRP-3 have been suggested to participate in innate immune signaling in adipose tissue (AT). This study investigates whether TLR-induced CAMP expression in adipocytes is antagonized by CTRP-3. METHODS: 3T3-L1 adipocytes were co-stimulated with TLR agonists (LPS, MALP-2, Pam3CSK4, pI:C) and recombinant CTRP-3. In a SIRS model, C57BL/6 wild-type mice were intraperitoneally (ip) injected with recombinant CTRP-3 prior to LPS. CAMP expression was analyzed by real-time PCR in AT of wild-type mice and in AT and primary adipocytes from transgenic mice lacking adipocyte CTRP-3 expression. Comparative transcriptome analysis by RNA seq. was applied in CTRP-3 KO adipocytes. RESULTS: In vitro, CTRP-3 antagonized TLR4- and TLR1/2-induced CAMP expression in adipocytes whereas TLR3- and TLR2/6-mediated induction of CAMP was not affected. in vivo, application of exogenous CTRP-3 dose-dependently antagonized LPS-induced CAMP expression in intra-abdominal AT. CAMP expression in total AT and in primary adipocytes of subcutaneous and intra-abdominal AT did not differ between wild-type mice and transgenic mice lacking adipocyte CTRP-3 expression. CONCLUSIONS: The study suggests a hypothetical role of CAMP in host defense not only against Gram-positive bacteria sensed by TLR1/2 and TLR2/6 but also against Gram-negative bacteria sensed by TLR4 and potentially against viruses sensed by TLR3. The machinery of TLR-mediated pro-inflammatory activation of the CAMP gene in adipocytes seems to be partly modulated by secreted adipokines belonging to the growing family of C1q/TNF-related proteins such as CTRP-3.

CTRP-3 Regulates NOD1-mediated Inflammation and NOD1 Expression in Adipocytes and Adipose Tissue.

The anti-inflammatory adipokine CTRP-3 might affect innate immune reactions such as NOD1. The impact of CTRP-3 on NOD1-mediated inflammation in adipocytes and monocytic cells as well as on NOD1 expression was investigated. Murine 3T3-L1 pre-adipocytes and adipocytes as well as human THP-1 monocyte-like cells were co-stimulated with the synthetic NOD1 agonist Tri-DAP and recombinant CTRP-3. Gonadal adipose tissue and primary adipocytes were obtained from a murine model carrying a knockout (KO) of CTRP-3 in adipocytes but not in stroma-vascular cells. Wildtype mice with lipopolysaccharide (LPS)-induced elevated NOD1 expression were treated with CTRP-3. Secreted inflammatory cytokines in cell supernatants were measured by ELISA and mRNA levels were quantified by RT-PCR. Pro-inflammatory chemokine and cytokine secretion (MCP-1, RANTES, TNFα) was induced by NOD1 activation in adipocytes and monocyte-like cells, and MCP-1 and RANTES release was effectively inhibited by pre-incubation of cells with CTRP-3. CTRP-3 also antagonized LPS-triggered induction of NOD1 gene expression in murine adipose tissue, whereas adipocyte CTRP-3 deficiency upregulated NOD1 expression in adipose tissue. CTRP-3 is an effective antagonist of peptidoglycan-induced, NOD1-mediated inflammation and of LPS-induced NOD1 expression. Since basal NOD1 expression is increased by adipocyte CTRP-3 deficiency, there have to be also inflammation-independent mechanisms of NOD1 expression regulation by CTRP-3.

Caspase-Cleaved Keratin 18 Measurements Identified Ongoing Liver Injury after Bariatric Surgery.

Bariatric surgery has emerged as an effective treatment option in morbidly obese patients with non-alcoholic fatty liver disease (NAFLD). However, worsening or new onset of non-alcoholic steatohepatitis (NASH) and fibrosis have been observed. Caspase-cleaved keratin 18 (ccK18) has been established as a marker of hepatocyte apoptosis, a key event in NASH development. Thus, ccK18 measurements might be feasible to monitor bariatric surgery patients. Clinical data and laboratory parameters were collected from 39 patients undergoing laparoscopic Roux-en-Y gastric bypass at six timepoints, prior to surgery until one year after the procedure. ccK18 levels were measured and a high-throughput analysis of serum adipokines and cytokines was carried out. Half of the cohort's patients (20/39) presented with ccK18 levels indicative of progressed liver disease. 21% had a NAFLD-fibrosis score greater than 0.676, suggesting significant fibrosis. One year after surgery, a mean weight loss of 36.87% was achieved. Six and twelve months after surgery, ccK18 fragments were significantly reduced compared to preoperative levels (p < 0.001). Yet nine patients did not show a decline in ccK18 levels ≥ 10% within one year postoperatively, which was considered a response to treatment. While no significant differences in laboratory parameters or ccK18 could be observed, they presented with a greater expression of leptin and fibrinogen before surgery. Consecutive ccK18 measurements monitored the resolution of NAFLD and identified non-responders to bariatric surgery with ongoing liver injury. Further studies are needed to elicit the pathological mechanisms in non-responders and study the potential of adipokines as prognostic markers.

[The effect of obesity on disease activity of inflammatory rheumatic diseases]. / Der Einfluss von Adipositas auf die Krankheitsaktivität bei entzündlich rheumatischen Erkrankungen.

One of the most recent scientific fields is the interaction between the immune system and metabolic processes. These interactions increasingly involve intracellular and extracellular signaling molecules and their receptors as well as molecular mechanisms that are used by both systems. The result of these intensive interactions is characterized by the term "metaflammation" and involves in particular, the ubiquitous adipose tissue present throughout the body. The links identified to date between the immune system and metabolism play a greater role in inflammatory rheumatic joint diseases than previously thought. In general, a markedly high body mass index (BMI) in particular, is associated with increased inflammatory activity and this is independent of the underlying disease entity. A higher BMI at the beginning of an immunomodulatory therapy also causes a more difficult response to the medication. Thus, the current scientific objective is to identify the individual "immuno-metabolic" pathways in order to apply the medications specifically to the site of action. Furthermore, all newer therapeutic agents, especially those specifically acting against individual immunological molecules, should be systematically analyzed with respect to their metabolic concomitant effects and their influence on metabolic comorbidities.

C1q/TNF-Related Protein 3 (CTRP-3) Deficiency of Adipocytes Affects White Adipose Tissue Mass but Not Systemic CTRP-3 Concentrations.

CTRP-3 (C1q/TNF-related protein-3) is an adipokine with endocrine and immunological function. The impact of adipocyte CTRP-3 production on systemic CTRP-3 concentrations and on adipocyte biology is unknown. A murine model of adipocyte CTRP-3 knockout (KO) was established (via the Cre/loxP system). Serum adipokine levels were quantified by ELISA and adipose tissue (AT) gene expression by real-time PCR. Preadipocytes were isolated from AT and differentiated into adipocytes. Comparative transcriptome analysis was applied in adipocytes and liver tissue. Body weight and AT mass were reduced in CTRP-3 KO mice together with decreased serum leptin. In primary cells from visceral AT of KO mice, expression of adiponectin, progranulin, and resistin was induced, while peroxisome proliferator activated receptor γ (PPARγ) was decreased. M1/M2 macrophage polarization markers were shifted to a more anti-inflammatory phenotype. CTRP-3 expression in AT did not contribute to serum concentrations. AT and liver morphology remained unaffected by CTRP-3 KO. Myelin transcription factor 1-like (Myt1l) was identified as a highly upregulated gene. In conclusion, adipocyte CTRP-3 has a role in adipogenesis and AT weight gain whereas adipocyte differentiation is not impaired by CTRP-3 deficiency. Since no effects on circulating CTRP-3 levels were observed, the impact of adipocyte CTRP-3 KO is limited to adipose tissue. Modified AT gene expression indicates a rather anti-inflammatory phenotype.