Role of the Stress- and Inflammation-Induced Cytokine GDF-15 in Cardiovascular Diseases: From Basic Research to Clinical Relevance.

Stress- and inflammation-induced growth differentiation factor-15 (GDF-15) is proposed as a biomarker for mortality and disease progression in patients with atherosclerosis and/or cardiovascular disease (CVD). The development of atherosclerotic lesions depends, among other factors, on inflammatory processes, oxidative stress, and impaired lipid homeostasis. As a consequence, activation and dysfunction of endothelial cells, release of chemokines, growth factors and lipid mediators occur. GDF-15 is suggested as an acute-phase modifier of transforming growth factor (TGF)-ßRII-dependent pro-inflammatory responses leading to rupture of atherosclerotic plaques, although the exact biological function is poorly understood to date. GDF-15 is upregulated in many disease processes, and its effects may be highly context-dependent. To date, it is unclear whether the upregulation of GDF-15 leads to disease progression or provides protection against disease. Concerning CVD, cardiomyocytes are already known to produce and release GDF-15 in response to angiotensin II stimulation, ischemia, and mechanical stretch. Cardiomyocytes, macrophages, vascular smooth muscle cells, endothelial cells, and adipocytes also release GDF-15 in response to oxidative as well as metabolic stress or stimulation with pro-inflammatory cytokines. Given the critically discussed pathophysiological and cellular functions and the important clinical significance of GDF-15 as a biomarker in CVD, we have summarized here the basic research findings on different cell types. In the context of cellular stress and inflammation, we further elucidated the signaling pathway of GDF-15 in coronary artery disease (CAD), the most common CVD in developing and industrial nations.

Diversity and substrate-specificity of green algae and other micro-eukaryotes colonizing amphibian clutches in Germany, revealed by DNA metabarcoding.

Amphibian clutches are colonized by diverse but poorly studied communities of micro-organisms. One of the most noted ones is the unicellular green alga, Oophila amblystomatis, but the occurrence and role of other micro-organisms in the capsular chamber surrounding amphibian clutches have remained largely unstudied. Here, we undertook a multi-marker DNA metabarcoding study to characterize the community of algae and other micro-eukaryotes associated with agile frog (Rana dalmatina) clutches. Samplings were performed at three small ponds in Germany, from four substrates: water, sediment, tree leaves from the bottom of the pond, and R. dalmatina clutches. Sampling substrate strongly determined the community compositions of algae and other micro-eukaryotes. Therefore, as expected, the frog clutch-associated communities formed clearly distinct clusters. Clutch-associated communities in our study were structured by a plethora of not only green algae, but also diatoms and other ochrophytes. The most abundant operational taxonomic units (OTUs) in clutch samples were taxa from Chlamydomonas, Oophila, but also from Nitzschia and other ochrophytes. Sequences of Oophila "Clade B" were found exclusively in clutches. Based on additional phylogenetic analyses of 18S rDNA and of a matrix of 18 nuclear genes derived from transcriptomes, we confirmed in our samples the existence of two distinct clades of green algae assigned to Oophila in past studies. We hypothesize that "Clade B" algae correspond to the true Oophila, whereas "Clade A" algae are a series of Chlorococcum species that, along with other green algae, ochrophytes and protists, colonize amphibian clutches opportunistically and are often cultured from clutch samples due to their robust growth performance. The clutch-associated communities were subject to filtering by sampling location, suggesting that the taxa colonizing amphibian clutches can drastically differ depending on environmental conditions.

Oxidized LDL-induced JAB1 influences NF-κB independent inflammatory signaling in human macrophages during foam cell formation.

BACKGROUND: Oxidized low-density lipoprotein (oxLDL) mediates the transformation of macrophages (MΦ) to cholesterol-rich foam cells and the release of pro-inflammatory cytokines during atherogenesis. JAB1 (Jun activation domain binding protein-1) is present in all stages of human plaques, involved in the Toll-like receptor-mediated activation of p38 mitogen-activated protein kinase (MAPK) and controls nuclear factor-kappa B (NF-κB) activation. Thus, we were interested in the role of JAB1 during foam cell formation of MΦ after oxLDL exposition. METHODS AND RESULTS: We found that JAB1 was present in CD68-immunoreactive (-ir) MΦ in atherosclerotic plaques of apolipoprotein E knockout (ApoE-/-) mice after a high cholesterol/fat diet. Furthermore, differentiated human U937 MΦ - incubated with oxLDL (4 h) to induce foam cell formation - showed a significant increase of JAB1 (50 µg/ml: 1.39 + 0.15-fold; 100 µg/ml: 1.80 + 0.26-fold; 200 µg/ml: 2.05 + 0.30-fold; p < 0.05) on the protein level compared to the control. Independent from JAB1 silencing, we found an increase of total cholesterol (TC), free cholesterol (FC) and cholesteryl ester (CE) after oxLDL exposition. However, siJAB1-MФ showed a reduction of tumor necrosis factor-alpha (TNF-α) (36%; p < 0.05 vs. non-transfected MФ) and interleukin (IL)-6 (30%; p < 0.05 vs. non-transfected MФ) mRNA expression, as well as TNF-α (46%; p < 0.05 vs. non-transfected MФ) and IL-6 (32%; p < 0.05 vs. non-transfected MФ) protein secretion after oxLDL exposition. In parallel with an upregulation of inflammatory cytokines (TNF-α, IL-6) after oxLDL exposition, we found a significant (p < 0.05) increase of 37% in p38 MAPK activation after 4 h oxLDL-treatment, independent from NF-kB signaling. In this context, we showed regional co-localization of JAB1 with p38 MAPK in atherosclerotic plaques of ApoE-/- mice. Moreover, we detected interaction of JAB1 with p38 MAPK in U937 cells. CONCLUSION: We demonstrate that oxLDL induces JAB1 expression and influences its cellular localization, whereby the p38 MAPK signaling pathway is modified with consequences for inflammation of human MΦ in foam cells and atherosclerotic lesions.

Microplastics in a small river: Occurrence and influencing factors along the river Oker, Northern Germany.

Much attention regarding the environmental pollution by plastics had focused on the Oceans. More recently, contamination of freshwater ecosystems has been addressed but information from smaller rivers in moderately populated catchments is still comparatively scarce. This study explored the microplastic (MP) occurrence in the small regional river Oker, Northern Germany (catchment area 1822 km2, population of ca. 500,000, discharge approx. 12 m3 s-1). MPs (fibers and fragments in the size range 0.3-5 mm, identification by microscopy) were found in all 10 in-stream samples collected along the course of the river, ranging between 28 and 134 particles m-3 with an overall average of 63 particles m-3. This MP concentration found in the small river Oker is similar to, or higher than, that reported for larger rivers in similar environments in Central Europe. On average, higher MP concentration was found at urban (71 particles m-3) compared to rural sampling sites (51 particles m-3). Within the Oker catchment, in-stream MP concentration showed no or low correlation to the catchment-scale factors of catchment size and population. Additional samples taken from three locations directly influenced by discharges of potential MP point sources confirmed wastewater treatment plants of different capacities and an urban rainwater sewer as sources. Our results support findings that MP concentrations in small rivers are crucially influenced by local sources, superimposing linear relationships to factors of catchment size and -population. They show that even small rivers draining moderately populated catchments may exhibit comparatively high concentrations of MPs, and thereby represent underestimated pathways of MP in the environment.

Effects of Cognitive and Physical Load of Acute Exercise on Inhibitory Control and Prefrontal Cortex Hemodynamics in Children.

INTRODUCTION: Evidence suggests that acute exercise benefits inhibitory control, but it remains unclear how physical and cognitive load influence this ability in preadolescent children, when faced with different types of distractors. We examined their moderating effects along with changes in prefrontal cortex hemodynamics. METHODS: Using a crossover design, 29 participants completed 10 min of exercise (with an interactive training wall) at 1) low physical and low cognitive load, 2) low physical and high cognitive load, 3) high physical and low cognitive load, and 4) high physical and high cognitive load in a randomized order. Before and after each condition, they performed a Standard and Affective Stroop task. During both tasks, the lateral oxygenation difference in the prefrontal cortex was measured by using functional near-infrared spectroscopy. RESULTS: For the Standard Stroop task, there was no effect of physical and cognitive load on performance. In contrast, exercise with low compared with high cognitive load was associated with a greater reduction of reaction time and increase in accuracy on the Affective Stroop task. This was accompanied by a decrease in lateral oxygenation difference on trials with low inhibitory control demands. CONCLUSIONS: Acute exercise with low compared with high cognitive demand benefits the ability to resolve emotional conflict, but the control over inhibition of nonemotional information remains unaffected. This effect of cognitive load is complemented by an increased efficiency of the left prefrontal cortex, when no emotional conflict resolution is required.

The Association of Physical Activity and Stress-induced Neurocognitive Impairments in Inhibitory Control in Children.

Background: Evaluation stress can impair inhibitory control, limiting the ability of children to perform cognitively. However, evidence on protective factors is lacking as stress-induced cognitive impairments are poorly understood. High physical activity has been related to better inhibitory control and has the potential to buffer the response to a stressor. We investigated the association of physical activity and stress-induced changes in inhibitory control as well as its underlying cognitive control processes (i.e., conflict monitoring and resolution). Method: Participants (10 to 13 y) with either low (N = 55) or high moderate-to-vigorous physical activity (N = 55) completed the Trier Social Stress Test for Children (TSST-C) and a control task in a randomized order. During both conditions, salivary cortisol was collected. Additionally, a computerized Stroop task was administered before and after the experimental conditions. The N200 and positive slow wave (PSW) components of event-related potentials elicited by the Stroop task were recorded using electroencephalography. Results: In comparison to the control task, the TSST-C elicited a pre-to post-test decrease of accuracy on incompatible trials. Path-analyses further revealed that this decrease was related to low physical activity and a reduced PSW amplitude. However, both the N200 and PSW amplitudes did not mediate the relation between physical activity groups and performance on the Stroop task. Conclusion: In children, evaluation stress decreases inhibitory control partly due to a reduced effectiveness of conflict resolution processes. Only children with high physical activity maintain inhibitory control after facing the stressor. However, this protective effect cannot be attributed to changes in conflict monitoring and resolution.

Cortical hemodynamics and inhibitory processing in preadolescent children with low and high physical activity.

Background: Preadolescent children undergo developmental changes in inhibitory control. Maintenance of high levels of moderate-to-vigorous-intensity physical activity (MVPA) has been suggested to promote its maturation. We compared inhibitory control between children with low and high MVPA as well as their inhibitory processing stream and changes in cortical hemodynamics. Method: 109 participants aged 10 to 13 years wore accelerometers over 7 days. Those with MVPA levels of 30 min/d or less and 60 min/d or more further performed a computerized Stroop Color-Word task. Electroencephalography and functional near-infrared spectroscopy were used to record changes in inhibitory processing and cortical hemodynamics, respectively. Results: An interaction of MVPA group and sex indicated better interference in highly-active boys, but the opposite pattern in girls. Independent from sex, the high compared to low MVPA group showed greater P300 and PSW amplitudes, whereas no group differences were found for N200, N450, and changes in cortical hemodynamics. Conclusion: Children with high MVPA differ from their less-active peers by a distinct inhibitory processing profile, which is characterized by altered allocation of attentional resources and conflict resolution. However, these alterations do not necessarily translate into better performance, especially since MVPA is linked with higher inhibitory control in boys only.

PACAP regulates VPAC1 expression, inflammatory processes and lipid homeostasis in M1- and M2-macrophages.

Background: Pituitary adenylate cyclase-activating polypeptide (PACAP) acts as an anti-atherogenic neuropeptide and plays an important role in cytoprotective, as well as inflammatory processes, and cardiovascular regulation. Therefore, the aim of this study is to investigate the regulatory effects of PACAP and its receptor VPAC1 in relation to inflammatory processes and lipid homeostasis in different macrophage (MΦ) subtypes. Methods: To investigate the role of PACAP deficiency in the pathogenesis of atherosclerosis under standard chow (SC) or cholesterol-enriched diet (CED) in vivo, PACAP-/- mice were crossbred with ApoE-/- to generate PACAP-/-/ApoE-/- mice. Lumen stenosis in the aortic arch and different MΦ-subtypes were analyzed in atherosclerotic plaques by quantitative immunohistochemistry. Undifferentiated bone marrow-derived cells (BMDC) from 30-weeks-old ApoE-/- and PACAP-/-/ApoE-/- mice were isolated, differentiated into BMDM1- and BMDM2-MΦ, and incubated with oxidized low-density lipoprotein (oxLDL). In addition, PMA-differentiated human THP-1 MΦ were further differentiated into M1-/M2-MΦ and subsequently treated with PACAP38, the VPAC1 agonist [(Ala11,22,28)VIP], the antagonist (PG 97-269), and/or oxLDL. Uptake/accumulation of oxLDL was analyzed by oxLDL-DyLight™488 and Bodipy™ 493/503. The mRNA expression was analyzed by qRT-PCR, protein levels by Western blot, and cytokine release by ELISA. Results: In vivo, after 30 weeks of SC, PACAP-/-/ApoE-/- mice showed increased lumen stenosis compared with ApoE-/- mice. In atherosclerotic plaques of PACAP-/-/ApoE-/- mice under CED, immunoreactive areas of VPAC1, CD86, and CD163 were increased compared with ApoE-/- mice. In vitro, VPAC1 protein levels were increased in PACAP-/-/ApoE-/- BMDM compared with ApoE-/- BMDM, resulting in increased TNF-α mRNA expression in BMDM1-MΦ and decreased TNF-α release in BMDM2-MΦ. Concerning lipid homeostasis, PACAP deficiency decreased the area of lipid droplets in BMDM1-/M2-MΦ with concomitant increasing adipose differentiation-related protein level. In THP-1 M1-/M2-MΦ, the VPAC1 antagonist increased the uptake of oxLDL, whereas the VPAC1 agonist decreased the oxLDL-induced intracellular triglyceride content. Conclusion: Our data suggest that PACAP via VPAC1 signaling plays an important regulatory role in inflammatory processes in atherosclerotic plaques and in lipid homeostasis in different MΦ-subtypes, thereby affecting foam cell formation. Therefore, VPAC1 agonists or PACAP may represent a new class of anti-atherogenic therapeutics.

Life in plastic, it's not fantastic: Sublethal effects of polyethylene microplastics ingestion throughout amphibian metamorphosis.

Microplastics (MP) are an abundant, long-lasting, and widespread type of environmental pollution that is of increasing concern as it might pose a serious threat to ecosystems and species. However, these threats are still largely unknown for amphibians. Here, we used the African clawed frog (Xenopus laevis) as a model species to investigate whether polyethylene MP ingestion affects amphibian growth and development and leads to metabolic changes across two consecutive life stages (larvae and juveniles). Furthermore, we examined whether MP effects were more pronounced at higher rearing temperatures. Larval growth, development, and body condition were recorded, and standard metabolic rate (SMR) and levels of stress hormone (corticosterone, CORT) were measured. We determined variation in size, morphology, and hepatosomatic index in juveniles to identify any potential consequences of MP ingestion across metamorphosis. In both life stages, MP accumulation in the body was assessed. MP ingestion was found to result in sublethal effects on larval growth, development, and metabolism, to lead to allometric carry-over effects on juvenile morphology, and to accumulate in the specimens at both life stages. In larvae, SMR and developmental rate increased in response to MP ingestion; there additionally was a significant interaction of MP ingestion and temperature on development. CORT levels were higher in larvae that ingested MP, except at higher temperature. In juveniles, body was wider, and extremities were longer in animals exposed to MP during the larval stage; a high rearing temperature in combination with MP ingestion counteracted this effect. Our results provide first insights into the effects of MP on amphibians throughout metamorphosis and demonstrate that juvenile amphibians may act as a pathway for MP from freshwater to terrestrial environments. To allow for generalizations across amphibian species, future experiments need to consider the field prevalence and abundance of different MP in amphibians at various life stages.

Switch of PMCA4 splice variants in bovine epididymis results in altered isoform expression during functional sperm maturation.

Ca(2+) and Ca(2+)-dependent signals are essential for sperm maturation and fertilization. In mouse sperm the plasma membrane Ca(2+)-ATPase (PMCA) isoform 4 plays a crucial role in Ca(2+) transport. The two major splice variants of PMCA4 are PMCA4a and PMCA4b. PMCA4a differs from PMCA4b in the mechanism of calmodulin binding and activation. PMCA4a shows a much higher basal activity and is more effective than PMCA4b in returning Ca(2+) to resting levels. Knock-out mice carrying a PMCA4-null mutation are infertile because their sperm cannot achieve a hyperactivated state of motility. As sperm reach functional maturity during their transit through the epididymis, the expression of PMCA4a and 4b was assessed in bull testis and epididymis. Quantitative PCR revealed that PMCA4b is the major splice variant in testis, caput, and corpus epididymidis. In contrast, PMCA4a is the major splice variant in cauda epididymidis, whereas sperm are transcriptionally silent. Immunohistochemical staining using a new antibody against bovine PMCA4a located the PMCA4a to the apical membrane of the epithelium of cauda epididymidis, whereas testis, caput, and corpus epididymidis were negative. Western blotting of testis, epididymis, and sperm isolated from caput and cauda epididymidis showed a much higher level of PMCA4a in cauda epididymidis and sperm from cauda epididymidis compared with testis membranes and sperm from caput epididymidis. These findings suggest that PMCA4a is transferred to bovine sperm membranes in cauda epididymidis. This isoform switch may facilitate a higher calcium turnover in sperm necessary to traverse the female genital tract.

GDF-15 Deficiency Reduces Autophagic Activity in Human Macrophages In Vitro and Decreases p62-Accumulation in Atherosclerotic Lesions in Mice.

(1) Background: Growth differentiation factor-15 (GDF-15) is associated with cardiovascular diseases and autophagy in human macrophages (MΦ). Thus, we are interested in investigating autophagic mechanisms with special respect to the role of GDF-15. (2) Methods: Recombinant (r)GDF-15 and siRNA GDF-15 were used to investigate the effects of GDF-15 on autophagic and lysosomal activity, as well as autophagosome formation by transmission electron microscopy (TEM) in MΦ. To ascertain the effects of GDF-15-/- on the progression of atherosclerotic lesions, we used GDF-15-/-/ApoE-/- and ApoE-/- mice under a cholesterol-enriched diet (CED). Body weight, body mass index (BMI), blood lipid levels and lumen stenosis in the brachiocephalic trunk (BT) were analyzed. Identification of different cell types and localization of autophagy-relevant proteins in atherosclerotic plaques were performed by immunofluorescence. (3) Results: siGDF-15 reduced and, conversely, rGDF-15 increased the autophagic activity in MΦ, whereas lysosomal activity was unaffected. Autophagic degradation after starvation and rGDF-15 treatment was observed by TEM. GDF-15-/-/ApoE-/- mice, after CED, showed reduced lumen stenosis in the BT, while body weight, BMI and triglycerides were increased compared with ApoE-/- mice. GDF-15-/- decreased p62-accumulation in atherosclerotic lesions, especially in endothelial cells (ECs). (4) Conclusion: GDF-15 seems to be an important factor in the regulation of autophagy, especially in ECs of atherosclerotic lesions, indicating its crucial pathophysiological function during atherosclerosis development.

PAC1 deficiency attenuates progression of atherosclerosis in ApoE deficient mice under cholesterol-enriched diet.

The neuropeptide, pituitary adenylate cyclase-activating polypeptide (PACAP) is vasoactive and cytoprotective and exerts immunoregulatory functions throughout the nervous, neuroendocrine cardiovascular and immune systems in health and disease. PACAP mainly acts through PAC1 receptor signaling in neuronal communication, but the role of PAC1 in immune regulation of atherosclerosis is not known. Here, we generated PAC1-/-/ApoE-/- mice to test, whether PAC1-/- influences plasma cholesterol-/triglyceride levels and/or atherogenesis in the brachiocephalic trunk (BT) seen in ApoE-/- mice, under standard chow (SC) or cholesterol-enriched diet (CED). Furthermore, the effect of PAC1-/-, on inflammatory, autophagy-, apoptosis- and necroptosis-relevant proteins in atherosclerotic plaques was determined. In plaques of PAC1-/-/ApoE-/- mice fed a SC, the immunoreactivity for apoptotic, autophagic, necroptotic and proinflammatory proteins was increased, however, proliferation was unaffected. Interestingly, without affecting hyperlipidemia, PAC1-/- in ApoE-/- mice remarkably reduced CED-induced lumen stenosis seen in ApoE-/- mice. Thus, PAC1-/- allows unchecked inflammation, necroptosis and decreased proliferation during SC, apparently priming the BT to develop reduced atheroma under subsequent CED. Remarkably, no differences in inflammation/necroptosis signatures in the atheroma under CED between PAC1-/-/ApoE-/- and ApoE-/- mice were observed. These data indicate that selective PAC1 antagonists should offer potential as a novel class of atheroprotective therapeutics, especially during hypercholesterolemia.

Accelerated prion replication in, but prolonged survival times of, prion-infected CXCR3-/- mice.

Prion diseases have a significant inflammatory component. Glia activation, which is associated with increased production of cytokines and chemokines, may play an important role in disease development. Among the chemokines upregulated highly and early upregulated during scrapie infections are ligands of CXCR3. To gain more insight into the role of CXCR3 in a prion model, CXCR3-deficient (CXCR3(-/-)) mice were infected intracerebrally with scrapie strain 139A and characterized in comparison to similarly infected wild-type controls. CXCR3(-/-) mice showed significantly prolonged survival times of up to 30 days on average. Surprisingly, however, they displayed accelerated accumulation of misfolded proteinase K-resistant prion protein PrP(Sc) and 20 times higher infectious prion titers than wild-type mice at the asymptomatic stage of the disease, indicating that these PrP isoforms may not be critical determinants of survival times. As demonstrated by immunohistochemistry, Western blotting, and gene expression analysis, CXCR3-deficient animals develop an excessive astrocytosis. However, microglia activation is reduced. Quantitative analysis of gliosis-associated gene expression alterations demonstrated reduced mRNA levels for a number of proinflammatory factors in CXCR3(-/-) compared to wild-type mice, indicating a weaker inflammatory response in the knockout mice. Taken together, this murine prion model identifies CXCR3 as disease-modifying host factor and indicates that inflammatory glial responses may act in concert with PrP(Sc) in disease development. Moreover, the results indicate that targeting CXCR3 for treatment of prion infections could prolong survival times, but the results also raise the concern that impairment of microglial migration by ablation or inhibition of CXCR3 could result in increased accumulation of misfolded PrP(Sc).

Data on autophagy markers in human macrophages exposed to oxLDL and growth differentiation factor-15.

Growth differentiation factor-15 (GDF-15) is a member of the TGF-ß superfamily, identical to MΦ-inhibitory cytokine-1 (MIC-1). GDF-15 is associated with e.g. cardiovascular disease, inflammation and development of atherosclerosis and is highly expressed in macrophages (MΦ) of atherosclerotic lesions. Moreover, there exists an indication for the involvement of oxidized-low density lipoprotein (oxLDL) uptake and autophagic processes by MΦ regarding arteriosclerotic progression. Thus, we were interested to investigate a potential regulatory effect of GDF-15 on autophagy signaling pathway in human MΦ during foam cell formation. Here, we present western blot data of ATG5, ATG12/ATG5-complex and p62 regarding the GDF-15 concentration. For further interpretation of the data presented in this article, please see the research article "Growth differentiation factor-15 regulates oxLDL-induced lipid homeostasis and autophagy in human macrophages" [1].

Growth differentiation factor-15 regulates oxLDL-induced lipid homeostasis and autophagy in human macrophages.

BACKGROUND AND AIMS: Growth differentiation factor-15 (GDF-15)/macrophage inhibitory cytokine-1 (MIC-1/GDF15) is associated with cardiovascular disease, inflammation and development of atherosclerosis and is highly expressed in macrophages (MΦ) of atherosclerotic lesions. Thus, we were interested in investigating the influence of GDF-15 in lipid homeostasis and autophagy in human MΦ during foam cell formation. METHODS AND RESULTS: Oxidized-low density lipoprotein (50 µg/ml oxLDL), recombinant (r)GDF-15, transiently silenced GDF-15 (siGDF-15 MΦ), as well as with negative siRNA transfected (nsiGDF-15 MΦ) PMA-differentiated human THP-1 MΦ, were used to investigate the effects of GDF-15 on autophagic processes and lipid accumulation. Oil Red O staining revealed that rGDF-15 alone, but also in combination with oxLDL, significantly increased the lipid accumulation in THP-1 MΦ; a reverse effect was detected in siGDF-15 MΦ. Western-blot analyses and confocal laser scanning microscopy showed an increase of Atg5, Atg12/Atg5 protein complex and p62 protein in THP-1 MΦ co-incubated with rGDF-15 and oxLDL, as well as an increase of p62 accumulation compared to rGDF-15-treated MΦ. Vice versa, siGDF-15 MΦ showed a reduced p62 accumulation compared to nsiGDF-15 MΦ. The present study indicates that GDF-15, especially in combination with oxLDL, regulates the expression of autophagy-relevant proteins (p62, Atg5 and Atg12/Atg5 protein complex) and p62 accumulation in human MΦ. CONCLUSIONS: GDF-15, in combination with oxLDL, impairs autophagic processes with consequences for lipid homeostasis in human MΦ, indicating its novel important pathophysiological role in atherosclerotic plaque development and progression.

Cortical hemodynamics and inhibitory processing in preadolescent children with low and high physical activity / Hemodinámica cortical y procesamiento inhibitorio en niños preadolescentes con baja y alta actividad física

Background: Preadolescent children undergo developmental changes in inhibitory control. Maintenance of high levels of moderate-to-vigorous-intensity physical activity (MVPA) has been suggested to promote its maturation. We compared inhibitory control between children with low and high MVPA as well as their inhibitory processing stream and changes in cortical hemodynamics. Method: 109 participants aged 10 to 13 years wore accelerometers over 7 days. Those with MVPA levels of 30 min/d or less and 60 min/d or more further performed a computerized Stroop Color-Word task. Electroencephalography and functional near-infrared spectroscopy were used to record changes in inhibitory processing and cortical hemodynamics, respectively. Results: An interaction of MVPA group and sex indicated better interference in highly-active boys, but the opposite pattern in girls. Independent from sex, the high compared to low MVPA group showed greater P300 and PSW amplitudes, whereas no group differences were found for N200, N450, and changes in cortical hemodynamics. Conclusion: Children with high MVPA differ from their less-active peers by a distinct inhibitory processing profile, which is characterized by altered allocation of attentional resources and conflict resolution. However, these alterations do not necessarily translate into better performance, especially since MVPA is linked with higher inhibitory control in boys only.(AU)

PACAP deficiency aggravates atherosclerosis in ApoE deficient mice.

Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) plays an important role in cytoprotection, inflammation and cardiovascular regulation. Thus, we studied the involvement of PACAP in atherogenesis. Differentiated human THP-1 macrophages (MΦ) were stimulated with oxidized low-density lipoproteins (oxLDL) and the influence of PACAP38 treatment on lipid content and TNF release was determined. To test the effect of PACAP deficiency (PACAP-/-) on the development of atherosclerosis under standard chow (SC) or cholesterol-enriched diet (CED) in vivo, PACAP-/- mice were crossbred with ApoE-/- to generate PACAP-/-/ApoE-/- mice. Blood cholesterol and triglyceride levels were quantified. Lumen stenosis in the brachiocephalic trunk, cellularity and amounts of pro-inflammatory as well as autophagy-, apoptosis- and necroptosis-relevant proteins were analysed in atherosclerotic plaques by quantitative immunohistochemistry. In vitro, PACAP38 inhibited oxLDL-induced intracellular lipid storage as well as TNF release in MФ. In vivo, after SC, but not under CED, PACAP-/-/ApoE-/- mice showed an increased lumen stenosis compared to ApoE-/- mice. In atherosclerotic plaques of PACAP-/-/ApoE-/- mice, the immunoreactive areas of TNF+, IL-1ß+, autophagic, apoptotic and necroptotic cells were increased. In contrast, the overall cell density was decreased compared to ApoE-/- under SC, while no differences were seen under CED. Similar plasma cholesterol levels were observed in PACAP-/-/ApoE-/- and ApoE-/- mice under the respective feeding regime. Thus, PACAP-/-/ApoE-/- mice represent a novel mouse model of accelerated atherosclerosis where CED is not required. Our data indicate that PACAP acts as an endogenous atheroprotective neuropeptide. Thus, stable PACAP agonists may have potential as anti-atherosclerotic therapeutics. The specific PACAP receptor(s) mediating atheroprotection remain(s) to be identified.

Prion infection of mice transgenic for human APPSwe: increased accumulation of cortical formic acid extractable Abeta(1-42) and rapid scrapie disease development.

Neuropathological, epidemiological and experimental data indicate a potential interrelationship between Alzheimer's disease and prion diseases. Proteolytic processing of amyloid precursor protein (APP) by beta-secretase was recently suggested to be controlled by prion protein expression. Here, we characterized the prion infection of Tg2576 mice, which overexpress the human APP(Swe) protein. Prion infection of Tg2576-mice led to an early death of the animals, which was preceded by a relatively short symptomatic stage. However, disease-associated gliosis and deposition of misfolded prion protein PrP(Sc) were identical in infected Tg2576-mice and non-transgenic littermate controls. To analyze the effect of prion infection on APP processing and generation of beta-amyloid we determined cortical levels of SDS- and formic acid (FA)-extractable forms of beta-amyloid (1-40) and (1-42) by ELISA. Formic acid-extractable Abeta (1-42) levels were 10-fold higher in infected versus uninfected Tg2576 mice whereas other forms of Abeta were essentially unaffected by the prion infection. Hence, the experimental model demonstrates that a prion infection of the CNS promotes selectively formation of FA-extractable Abeta(1-42) in Tg2576 mice.

Looking back - Looking forward: A novel multi-time slice weight-of-evidence approach for defining reference conditions to assess the impact of human activities on lake systems.

Lake ecosystems are sensitive recorders of environmental changes that provide continuous archives at annual to decadal resolution over thousands of years. The systematic investigation of land use changes and emission of pollutants archived in Holocene lake sediments as well as the reconstruction of contamination, background conditions, and sensitivity of lake systems offer an ideal opportunity to study environmental dynamics and consequences of anthropogenic impact that increasingly pose risks to human well-being. This paper discusses the use of sediment and other lines of evidence in providing a record of historical and current contamination in lake ecosystems. We present a novel approach to investigate impacts from human activities using chemical-analytical, bioanalytical, ecological, paleolimnological, paleoecotoxicological, archeological as well as modeling techniques. This multi-time slice weight-of-evidence (WOE) approach will generate knowledge on conditions prior to anthropogenic influence and provide knowledge to (i) create a better understanding of the effects of anthropogenic disturbances on biodiversity, (ii) assess water quality by using quantitative data on historical pollution and persistence of pollutants archived over thousands of years in sediments, and (iii) define environmental threshold values using modeling methods. This technique may be applied in order to gain insights into reference conditions of surface and ground waters in catchments with a long history of land use and human impact, which is still a major need that is currently not yet addressed within the context of the European Water Framework Directive.

Memantine treatment of complex regional pain syndrome: a preliminary report of six cases.

OBJECTIVES: Recent studies have confirmed the contribution of the central nervous system (CNS) to the pathogenesis of Complex Regional Pain Syndrome (CRPS), because animal models of neuropathic pain syndromes demonstrate an overexpression of N-methyl-D-aspartate-receptors in the CNS. The aim of this work was to study the influence of a central acting drug-the N-methyl-D-aspartate receptor antagonist Memantine-in patients with CRPS of one upper extremity. Here we present the results of 6 patients treated with Memantine for 8 weeks. METHODS: All patients developed CRPS after traumatic injury to one upper extremity. To document changes during the study, levels of pain were measured after clenching the hand using a numeric pain intensity scale ranging from 0 (no pain) to 10 (maximum pain). Motor symptoms were documented for the fingers (fingertips to palm and fingernails to table) and the wrist (flexion/extension). Furthermore, the force was analyzed using a JAMAR-Dynamometer and a Pinchmeter. For assessment of central changes, functional magnetic resonance imaging and magnetoencephalography were used to further document the results of other experiments in 1 patient. Autonomic changes were photographed and pictures were compared before and after treatment with Memantine. RESULTS: Six months after treatment with Memantine, all patients showed a significant decrease in their levels of pain which coincided with an improvement in motor symptoms and autonomic changes. The functional magnetic resonance imaging and magnetoencephalography results provided evidence of cortical reorganization [changes in somatotopic maps in the primary somatosensory cortex (S1)]. These changes returned to a cortical pattern comparable to the unaffected side after treatment with Memantine. DISCUSSION: Based on these first results, the use of Memantine for treatment of CRPS seems promising and supports the hypothesis of a CNS contribution to the pathogenesis and maintenance of neuropathic pain syndromes.