Comparative analysis of full-length 16s ribosomal RNA genome sequencing in human fecal samples using primer sets with different degrees of degeneracy.

Next-generation sequencing has revolutionized the field of microbiology research and greatly expanded our knowledge of complex bacterial communities. Nanopore sequencing provides distinct advantages, combining cost-effectiveness, ease of use, high throughput, and high taxonomic resolution through its ability to process long amplicons, such as the entire 16s rRNA genome. We examine the performance of the conventional 27F primer (27F-I) included in the 16S Barcoding Kit distributed by Oxford Nanopore Technologies (ONT) and that of a more degenerate 27F primer (27F-II) in the context of highly complex bacterial communities in 73 human fecal samples. The results show striking differences in both taxonomic diversity and relative abundance of a substantial number of taxa between the two primer sets. Primer 27F-I reveals a significantly lower biodiversity and, for example, at the taxonomic level of the phyla, a dominance of Firmicutes and Proteobacteria as determined by relative abundances, as well as an unusually high ratio of Firmicutes/Bacteriodetes when compared to the more degenerate primer set (27F-II). Considering the findings in the context of the gut microbiomes common in Western industrial societies, as reported in the American Gut Project, the more degenerate primer set (27F-II) reflects the composition and diversity of the fecal microbiome significantly better than the 27F-I primer. This study provides a fundamentally relevant comparative analysis of the in situ performance of two primer sets designed for sequencing of the entire 16s rRNA genome and suggests that the more degenerate primer set (27F-II) should be preferred for nanopore sequencing-based analyses of the human fecal microbiome.

Cardiopulmonary Profiling of Athletes with Post-Exertional Malaise after COVID-19 Infection-A Single-Center Experience.

(1) Background: Cardiopulmonary exercise testing (CPET) has been suggested by the European Society of Cardiology (ESC) for assessing the exercise limitations of apparently healthy individuals, but data on elite athletes regarding this test are scarce. (2) Methods: We analyzed CPET in elite (n = 43, 21.9 ± 3.7 years) and recreational (n = 40, 34.7 ± 13.0 years) athletes with persistent subjective exercise intolerance and post-exertional malaise (PEM) after COVID-19 infection. The primary outcome was the point prevalence of the adequate cardiopulmonary response (ACPR), defined by the presence of all of the following ESC criteria for apparently healthy individuals: (1) >100% of predicted peak oxygen consumption (predVO2peak), (2) VE/VCO2 < 30, (3) no exercise oscillatory ventilation (EOV), and (4) heart rate recovery of ≥12 beats/minute 1 min after exercise termination (HRR1). Results: ACPR occurred more frequently in elite athletes than in recreational athletes (70.0% vs. 39.5%; p = 0.005), mainly driven by the lower VE/VCO2 (<30: 97.7% vs. 65%, p < 0.001). Elite (11.6%) and recreational athletes (22.5%) showing a plateau of O2 pulse did not display ACPR. Conclusions: ACPR was not observed in all recreational and elite athletes with PEM. In particular, perturbed VE/VCO2 and the plateauing of O2 pulse are suitable for quantifying exercise limitations and may identify a high-risk population with long-COVID-19 syndrome who require their training intensities to be adapted.

Increased Density of Growth Differentiation Factor-15+ Immunoreactive M1/M2 Macrophages in Prostate Cancer of Different Gleason Scores Compared with Benign Prostate Hyperplasia.

Although growth differentiation factor-15 (GDF-15) is highly expressed in PCa, its role in the development and progression of PCa is unclear. The present study aims to determine the density of GDF-15+ cells and immune cells (M1-/M2 macrophages [MΦ], lymphocytes) in PCa of different Gleason scores (GS) compared to BPH. Immunohistochemistry and double immunofluorescence were performed on paraffin-embedded human PCa and BPH biopsies with antibodies directed against GDF-15, CD68 (M1 MΦ), CD163 (M2 MΦ), CD4, CD8, CD19 (T /B lymphocytes), or PD-L1. PGP9.5 served as a marker for innervation and neuroendocrine cells. GDF-15+ cell density was higher in all GS than in BPH. CD68+ MΦ density in GS9 and CD163+ MΦ exceeded that in BPH. GDF-15+ cell density correlated significantly positively with CD68+ or CD163+ MΦ density in extratumoral areas. Double immunoreactive GDF-15+/CD68+ cells were found as transepithelial migrating MΦ. Stromal CD68+ MΦ lacked GDF-15+. The area of PGP9.5+ innervation was higher in GS9 than in BPH. PGP9.5+ cells, occasionally copositive for GDF-15+, also occurred in the glandular epithelium. In GS6, but not in BPH, GDF-15+, PD-L1+, and CD68+ cells were found in epithelium within luminal excrescences. The degree of extra-/intra-tumoral GDF-15 increases in M1/M2Φ is proposed to be useful to stratify progredient malignancy of PCa. GDF-15 is a potential target for anti-tumor therapy.

Neurochemical Monitoring of Traumatic Brain Injury by the Combined Analysis of Plasma Beta-Synuclein, NfL, and GFAP in Polytraumatized Patients.

Traumatic brain injury (TBI) represents a major determining factor of outcome in severely injured patients. However, reliable brain-damage-monitoring markers are still missing. We therefore assessed brain-specific beta-synuclein as a novel blood biomarker of synaptic damage and measured the benchmarks neurofilament light chain (NfL), as a neuroaxonal injury marker, and glial fibrillary acidic protein (GFAP), as an astroglial injury marker, in patients after polytrauma with and without TBI. Compared to healthy volunteers, plasma NfL, beta-synuclein, and GFAP were significantly increased after polytrauma. The markers demonstrated highly distinct time courses, with beta-synuclein and GFAP peaking early and NfL concentrations gradually elevating during the 10-day observation period. Correlation analyses revealed a distinct influence of the extent of extracranial hemorrhage and the severity of head injury on biomarker concentrations. A combined analysis of beta-synuclein and GFAP effectively discriminated between polytrauma patients with and without TBI, despite the comparable severity of injury. Furthermore, we found a good predictive performance for fatal outcome by employing the initial plasma concentrations of NfL, beta-synuclein, and GFAP. Our findings suggest a high diagnostic value of neuronal injury markers reflecting distinct aspects of neuronal injury for the diagnosis of TBI in the complex setting of polytrauma, especially in clinical surroundings with limited imaging opportunities.

Protein Expression of the Microglial Marker Tmem119 Decreases in Association With Morphological Changes and Location in a Mouse Model of Traumatic Brain Injury.

The activation of microglia and the infiltration of macrophages are hallmarks of neuroinflammation after acute brain injuries, including traumatic brain injury (TBI). The two myeloid populations share many features in the post-injury inflammatory response, thus, being antigenically indistinguishable. Recently Tmem119, a type I transmembrane protein specifically expressed by microglia under physiological conditions, was proposed as a tool to differentiate resident microglia from blood-borne macrophages, not expressing it. However, the validity of Tmem119 as a specific marker of resident microglia in the context of acute brain injury, where microglia are activated and macrophages are recruited, needs validation. Our purpose was to investigate Tmem119 expression and distribution in relation to the morphology of brain myeloid cells present in the injured area after TBI. Mice underwent sham surgery or TBI by controlled cortical impact (CCI). Brains from sham-operated, or TBI mice, were analyzed by in situ hybridization to identify the cells expressing Tmem119, and by Western blot and quantitative immunofluorescence to measure Tmem119 protein levels in the entire brain regions and single cells. The morphology of Iba1+ myeloid cells was analyzed at different times (4 and 7 days after TBI) and several distances from the contused edge in order to associate Tmem119 expression with morphological evolution of active microglia. In situ hybridization indicated an increased Tmem119 RNA along with increased microglial complement C1q activation in the contused area and surrounding regions. On the contrary, the biochemical evaluation showed a drop in Tmem119 protein levels in the same areas. The Tmem119 immunoreactivity decreased in Iba1+ myeloid cells found in the contused cortex at both time points, with the cells showing the hypertrophic ameboid morphology having no Tmem119 expression. The Tmem119 was present on ramifications of resident microglia and its presence was decreased as a consequence of microglial activation in cortical areas close to contusion. Based on the data, we conclude that the decrease of Tmem119 in reactive microglia may depend on the process of microglial activation, which involves the retracting of their branchings to acquire an ameboid shape. The Tmem119 immunoreactivity decreases in reactive microglia to similar levels than the blood-borne macrophages, thus, failing to discriminate the two myeloid populations after TBI.

Reduced physical activity and weight gain are associated with an increase of depressive symptoms during the COVID-19 pandemic. A general practitioners' prospective observational study.

OBJECTIVES: We aimed to assess associations between depressive symptoms, lifestyle, and somatic symptoms during the COVID-19 pandemic. DESIGN: A prospective, observational study using a self-designed questionnaire. SETTING: Three general practitioners' (GP) offices in rural Germany. PARTICIPANTS: 271 adult patients without manifest cardiovascular or pulmonary disease with (n = 82) and without (n = 189) hypertension reporting to our GP offices. MAIN OUTCOME MEASURES: The reported increase of depressive symptoms (loneliness, sleeplessness, joylessness, listlessness) prior to the first documented case in Germany on 27.01.2020 (t0) as opposed to patients' health perception during the Corona pandemic (t1) was the primary outcome measure. The secondary outcome measures were changes in physical activity (PA), dyspnea and angina in the two groups. RESULTS: Out of 271 patients (50.8 ± 16.8 years, 55.1% females), 1.5% were tested positive for COVID-19. Overall, listlessness (8.5%, p = 0.001), sleeplessness (5.2%, p = 0.001) and joylessness (4.2%, p = 0.003) were increased. Dyspnea significantly increased (9.2%, p < 0.001) and employment status worsened (6.5%, p < 0.001). There were significant associations between the increase of depressive symptoms, weight increase (p = 0.017), and reduction in physical activity (p = 0.046). However, after adjusting for age, hypertensive patients did not show more depressive symptoms (p = 0.704), dyspnea (p = 0.063) or angina (p = 0.432), nor was there any difference in PA (p = 0.906) compared to healthy individuals. CONCLUSIONS: We demonstrate an association between the deterioration of depressive symptoms, weight gain, and reduced physical activity during COVID-19, both in hypertensives and healthy controls. Hypertension is no driver of symptom deterioration during the pandemic. The trial was registered in the German Clinical Trials Registry (DRKS00022157).

Vital capacity and valvular dysfunction could serve as non-invasive predictors to screen for exercise pulmonary hypertension in the elderly based on a new diagnostic score.

Introduction: Exercise pulmonary hypertension (exPH) has been defined as total pulmonary resistance (TPR) >3 mm Hg/L/min and mean pulmonary artery pressure (mPAP) >30 mm Hg, albeit with a considerable risk of false positives in elderly patients with lower cardiac output during exercise. Methods: We retrospectively analysed patients with unclear dyspnea receiving right heart catheterisation at rest and exercise (n=244) between January 2015 and January 2020. Lung function testing, blood gas analysis, and echocardiography were performed. We elaborated a combinatorial score to advance the current definition of exPH in an elderly population (mean age 67.0 years±11.9). A stepwise regression model was calculated to non-invasively predict exPH. Results: Analysis of variables across the achieved peak power allowed the creation of a model for defining exPH, where three out of four criteria needed to be fulfilled: Peak power ≤100 Watt, pulmonary capillary wedge pressure ≥18 mm Hg, pulmonary vascular resistance >3 Wood Units, and mPAP ≥35 mm Hg. The new scoring model resulted in a lower number of exPH diagnoses than the current suggestion (63.1% vs. 78.3%). We present a combinatorial model with vital capacity (VCmax) and valvular dysfunction to predict exPH (sensitivity 93.2%; specificity 44.2%, area under the curve 0.73) based on our suggested criteria. The odds of the presence of exPH were 2.1 for a 1 l loss in VCmax and 3.6 for having valvular dysfunction. Conclusion: We advance a revised definition of exPH in elderly patients in order to overcome current limitations. We establish a new non-invasive approach to predict exPH by assessing VCmax and valvular dysfunction for early risk stratification in elderly patients.

The Feasibility of High-Intensity Interval Training in Patients with Intensive Care Unit-Acquired Weakness Syndrome Following Long-Term Invasive Ventilation.

BACKGROUND: Intensive care unit-acquired weakness syndrome (ICUAWS) can be a consequence of long-term mechanical ventilation. Despite recommendations of early patient mobilisation, little is known about the feasibility, safety and benefit of interval training in early rehabilitation facilities (ERF) after long-term invasive ventilation. METHODS AND RESULTS: We retrospectively analysed two established training protocols of bicycle ergometry in ERF patients after long-term (> 7 days) invasive ventilation (n = 46). Patients conducted moderate continuous (MCT, n = 24, mean age 70.3 ± 10.1 years) or high-intensity interval training (HIIT, n = 22, mean age 63.6 ± 12.6 years). The intensity of training was monitored with the BORG CR10 scale (intense phases ≥ 7/10 and moderate phases ≤ 4/10 points). The primary outcome was improvement (∆-values) of six-minute-walk-test (6 MWT), while the secondary outcomes were improvement of vital capacity (VCmax), forced expiratory volume in 1 s (FEV1), maximal inspiratory pressure (PImax) and functional capabilities (functional independence assessment measure, FIM/FAM and Barthel scores) after 3 weeks of training. No adverse events were observed. There was a trend towards a greater improvement of 6 MWT in HIIT than MCT (159.5 ± 64.9 m vs. 120.4 ± 60.4 m; p = .057), despite more days of invasive ventilation (39.6 ± 16.8 days vs. 26.8 ± 16.2 days; p = .009). VCmax (∆0.5l ± 0.6 vs. ∆0.5l ± 0.3; p = .462), FEV1 (∆0.2l ± 0.3 vs. ∆0.3l ± 0.2; p = .218) PImax (∆0.8 ± 1.1 kPa vs. ∆0.7 ± 1.3pts; p = .918) and functional status (FIM/FAM: ∆29.0 ± 14.8pts vs. ∆30.9 ± 16.0pts; p = .707; Barthel: ∆28.9 ± 16.0 pts vs. ∆25.0 ± 10.5pts; p = .341) improved in HIIT and MCT. CONCLUSIONS: We demonstrate the feasibility and safety of HIIT in the early rehabilitation of ICUAWS patients. Larger trials are necessary to find adequate dosage of HIIT in ICUAWS patients.

Outpatient Management of Oligosymptomatic Patients with respiratory infection in the era of SARS-CoV-2: Experience from rural German general practitioners.

BACKGROUND: Covid-19 is causing a pandemic and forces physicians to restructure their work. We want to share our experience in the outpatient management of potentially-infected patients with special consideration of altered national test strategies during the crisis. METHODS: We analysed patients with respiratory symptoms reporting to our three rural general practitioner (GP) offices in North Rhine-Westphalia, Germany, from 27.01-20.04.2020 (n = 489 from a total of 6090 patients). A history of symptoms was taken at the doorstep following a specific questionnaire. Patients with respiratory symptoms were examined in a separated isolation area, while the others were allowed to enter the office. We applied the first recommended algorithm of the German Robert Koch Institute (RKI) to test suspected patients and compared our results with an adapted, more liberal version of the RKI, which is currently applied in Germany. RESULTS: Eighty patients (16.36%, mean age: 47.03 years+ - 18.08) were sent to a nasopharyngeal smear. Five patients (6.25%) proved to be positive, four of whom had established risk factors for COVID-19. Overall, the most common symptoms were cough (83.75%), sore throat (71.25%), as well as myalgia and fatigue (66.25%). The most common diagnoses were rhinopharyngitis (37.22%) and acute bronchitis (30.27%). A sore throat was more common in positively-tested patients (80% vs. 12%). Applying the first RKI test strategy yielded 6.25% of positive tests (n = 80), while the more liberal later RKI recommendation would have achieved 1.36% positive tests from 369 patients. No positive test was missed by applying the conservative strategy. None of our employees called in sick during this period, which emphasises the efficacy and safety of our screening methods. CONCLUSION: A clinical distinction between ordinary respiratory infections and COVID-19 is not possible in a low-prevalence population. Our model to prevent unprotected physical contact, screen patients in front of the office with protective equipment, and examine respiratory infections in separated areas works in the GP setting without overt health risks for employees. Thus, this approach should be used as a GP standard to uphold patient care without major health risks for the personnel. Large multi-centre studies are necessary to work out the most suitable test strategy.

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.

Prostate cancer tissues with positive TMPRSS2-ERG-gene-fusion status may display enhanced nerve density.

Innervation of prostate cancer (CaP) tissue favors tumor progression and metastasis but the regulation of innervation in CaP is unclear. The oncogenic transcription factor ERG is commonly induced by a typical TMPRSS2-ERG (TE) gene fusion in CaP and may affect innervation. Here, we analyzed whether nerve density of CaP tissue is related to TE status or perineural infiltration status of CaP tissue. In parallel, we measured several members of the neuropilin/plexin/semaphorin family (NRP, PLXN, and SEMA) as possible targets mediating innervation. The TE-gene-fusion status was determined at the mRNA level in CaP tissues by nested RT-PCR. Transcript levels were analyzed by quantitative RT-PCR in CaP tissue or cell line homogenate. ERG was analyzed by immunostaining, and the nerve density was evaluated by immunostaining for PGP9.5 and axonal neurofilament. Data were analyzed by correlation (Spearman), linear regression, Mann-Whitney U test, and contingency table analyses. TE-positive (TE-1) vs. TE-negative (TE-0) CaP tissues displayed significantly enhanced ERG-mRNA levels (TE-0: -4.183; TE-1: -2.994, P < 0.001) and ERG immunostaining (Erg-IH score; TE-0: 0.4211; TE-1: 1.391; P < 0.0001). Notably, the nerve density was significantly increased in CaP tissue samples with positive TE status compared to negative TE status (TE-0, ND score = 1.5; TE-1, ND score = 2.0; P <0.01). NRP1, NRP2, PLXNA2, PLXNB1, SEMA3A, and SEMA4B mRNAs were detectable in CaP tissues and CaP cell lines at quite heterogeneous levels. In CaP tissues, we observed significant positive correlations of ERG with NRP2, PLXNA2, PLXNB1, and SEMA4B. TE-positive CaP tissues displayed enhanced nerve density. ERG correlated with some NRP/PLXN/SEMA components suggesting possible regulatory relevance of ERG for CaP innervation.

Pituitary Adenylate Cyclase-Activating Peptide (PACAP)-Glutamate Co-transmission Drives Circadian Phase-Advancing Responses to Intrinsically Photosensitive Retinal Ganglion Cell Projections by Suprachiasmatic Nucleus.

Results from a variety of sources indicate a role for pituitary adenylate cyclase-activating polypeptide (PACAP) in light/glutamate-induced phase resetting of the circadian clock mediated by the retinohypothalamic tract (RHT). Attempts to block or remove PACAP's contribution to clock-resetting have generated phenotypes that differ in their responses to light or glutamate. For example, previous studies of circadian behaviors found that period-maintenance and early-night phase delays are intact in PACAP-null mice, yet there is a consistent deficit in behavioral phase-resetting to light stimulation in the late night. Here we report rodent stimulus-response characteristics of PACAP release from the RHT, and map these to responses of the suprachiasmatic nucleus (SCN) in intact and PACAP-deficient mouse hypothalamus with regard to phase-resetting. SCN of PACAP-null mice exhibit normal circadian rhythms in neuronal activity, but are "blind" to glutamate stimulating phase-advance responses in late night, although not in early night, consistent with previously reported selective lack of late-night light behavioral responsiveness of these mice. Induction of CREB phosphorylation, a hallmark of the light/glutamate response of the SCN, also is absent in SCN-containing ex vivo slices from PACAP-deficient mouse hypothalamus. PACAP replacement to the SCN of PACAP-null mice restored wild-type phase-shifting of firing-rate patterns in response to glutamate applied to the SCN in late night. Likewise, ex vivo SCN of wild-type mice post-orbital enucleation are unresponsive to glutamate unless PACAP also is restored. Furthermore, we demonstrate that the period of efficacy of PACAP at SCN nerve terminals corresponds to waxing of PACAP mRNA expression in ipRGCs during the night, and waning during the day. These results validate the use of PACAP-deficient mice in defining the role and specificity of PACAP as a co-transmitter with glutamate in ipRGC-RHT projections to SCN in phase advancing the SCN circadian rhythm in late night.

Distribution pattern and molecular signature of cholinergic tuft cells in human gastro-intestinal and pancreatic-biliary tract.

Despite considerable recent insight into the molecular phenotypes and type 2 innate immune functions of tuft cells in rodents, there is sparse knowledge about the region-specific presence and molecular phenotypes of tuft cells in the human digestive tract. Here, we traced cholinergic tuft cells throughout the human alimentary tract with immunohistochemistry and deciphered their region-specific distribution and biomolecule coexistence patterns. While absent from the human stomach, cholinergic tuft cells localized to villi and crypts in the small and large intestines. In the biliary tract, they were present in the epithelium of extra-hepatic peribiliary glands, but not observed in the epithelia of the gall bladder and the common duct of the biliary tract. In the pancreas, solitary cholinergic tuft cells were frequently observed in the epithelia of small and medium-size intra- and inter-lobular ducts, while they were absent from acinar cells and from the main pancreatic duct. Double immunofluorescence revealed co-expression of choline acetyltransferase with structural (cytokeratin 18, villin, advillin) tuft cell markers and eicosanoid signaling (cyclooxygenase 1, hematopoietic prostaglandin D synthase, 5-lipoxygenase activating protein) biomolecules. Our results indicate that region-specific cholinergic signaling of tuft cells plays a role in mucosal immunity in health and disease, especially in infection and cancer.

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.

SOD1G93A Mutant Mice Develop a Neuroinflammation-Independent Dendropathy in Excitatory Neuronal Subsets of the Olfactory Bulb and Retina.

Nonmotor neuron-related pathology is a feature of amyotrophic lateral sclerosis (ALS), both in patients and in animal models. There is emerging evidence that sensory systems (olfaction and vision) are affected in humans. Here, we asked whether such sensory neuropathology is recapitulated in the superoxide dismutase 1 (SOD1G93A) mouse model of ALS. Neuronal vacuolization in olfaction and vision pathways was assessed in tissue sections from presymptomatic and symptomatic disease stages, and compared to wild type. In both, the olfactory bulb and retina, vacuolization started around postnatal day 60, and vacuole sizes increased until disease end-stage. Notably, vacuolization was largely restricted to the external plexiform layer of the olfactory bulb and to the inner plexiform layer of the retina. In both layers, hSOD1-immunoreactive vacuoles localized to dendrites of excitatory neurons. Downstream olfaction and vision pathway fiber tracts and relay stations did not display obvious vacuolization. Finally, on a morphological level, there was no evidence for an activation of astrocytes and microglia in the 2 affected areas. Thus, we identified a new pathology hallmark in SOD1G93A ALS mice: a glutamatergic sensory neuron dendropathy restricted to olfactory bulb mitral cells and retinal ganglionic cells.

Preclinical evaluation of PAC1 targeting with radiolabeled Maxadilan.

There is an ongoing search for new tracers to optimize imaging of beta cell-derived tumors (insulinomas). The PAC1 receptor, expressed by insulinomas, can be used for targeting of these tumors. Here, we investigated whether radiolabeled maxadilan could be used for insulinoma imaging. Maxadilan was C- or N-terminally conjugated with DTPA (termed maxadilan-DPTA or DTPA-maxadilan respectively). BALB/c nude mice bearing subcutaneous INS-1 tumors were injected with either In-111-labeled maxadilan-DTPA or In-111-DTPA-maxadilan. Biodistribution studies were carried out at 1, 2 and 4 hours after injection and SPECT/CT imaging 1 and 4 hours after injection of maxadilan-DTPA-111In. Radiolabeling of maxadilan-DTPA (680 MBq/nmol) was more efficient than of DTPA-maxadilan (55 MBq/nmol). Conjugation with DTPA slightly reduced receptor binding affinity in vitro: IC50 values were 3.2, 21.0 and 21.0 nM for maxadilan, natIn-DTPA-maxadilan and maxadilan-DTPA-natIn respectively. Upon i.v. injection maxadilan-DTPA-111In accumulated specifically in INS-1 tumors (7.30 ± 1.87%ID/g) and in the pancreas (3.82 ± 0.22%ID/g). INS-1 tumors were clearly visualized by small animal SPECT/CT. In conclusion, this study showed that the high affinity of maxadilan to the PAC1 receptor was maintained after DTPA conjugation. Furthermore, radiolabeled maxadilan-DTPA accumulated specifically in INS-1 tumors and, therefore, may qualify as a useful tracer to image insulinomas.

Evidence for the absence of visceral pain in C57BL6/N mice subjected to therapeutically relevant O3/O2-pneumoperitoneum.

Each different gas that is used to induce a pneumoperitoneum (PP) exhibits individual effects within the peritoneal cavity. This might include adverse effects such as pain and/or inflammatory reactions. The acute effects of ozonized oxygen (O3/O2), a highly oxidative gas mixture, after being insufflated into the peritoneal cavity are analysed in this study. Using the abdominal constriction response ('writhing') assay of chemical nociception in C57BL6/N mice, O3/O2-PP was found not to be associated with visible pain responses and did not alter the c-fos expression in the spinal cord. In addition, mRNA expression levels of the pro-inflammatory cytokines, interleukin (IL)-1ß and IL-6, were found unaltered in the spleen 2 h after insufflation. In conclusion, O3/O2-PP is free of adverse pain and does not trigger inflammatory immune responses.

Disruption of calcitonin gene-related peptide signaling accelerates muscle denervation and dampens cytotoxic neuroinflammation in SOD1 mutant mice.

Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease. Neuronal vacuolization and glial activation are pathologic hallmarks in the superoxide dismutase 1 (SOD1) mouse model of ALS. Previously, we found the neuropeptide calcitonin gene-related peptide (CGRP) associated with vacuolization and astrogliosis in the spinal cord of these mice. We now show that CGRP abundance positively correlated with the severity of astrogliosis, but not vacuolization, in several motor and non-motor areas throughout the brain. SOD1 mice harboring a genetic depletion of the ßCGRP isoform showed reduced CGRP immunoreactivity associated with vacuolization, while motor functions, body weight, survival, and astrogliosis were not altered. When CGRP signaling was completely disrupted through genetic depletion of the CGRP receptor component, receptor activity-modifying protein 1 (RAMP1), hind limb muscle denervation, and loss of muscle performance were accelerated, while body weight and survival were not affected. Dampened neuroinflammation, i.e., reduced levels of astrogliosis in the brain stem already in the pre-symptomatic disease stage, and reduced microgliosis and lymphocyte infiltrations during the late disease phase were additional neuropathology features in these mice. On the molecular level, mRNA expression levels of brain-derived neurotrophic factor (BDNF) and those of the anti-inflammatory cytokine interleukin 6 (IL-6) were elevated, while those of several pro-inflammatory cytokines found reduced in the brain stem of RAMP1-deficient SOD1 mice at disease end stage. Our results thus identify an important, possibly dual role of CGRP in ALS pathogenesis.

Loss of cerebellar neurons in the progression of lentiviral disease: effects of CNS-permeant antiretroviral therapy.

BACKGROUND: The majority of investigations on HIV-associated neurocognitive disorders (HAND) neglect the cerebellum in spite of emerging evidence for its role in higher cognitive functions and dysfunctions in common neurodegenerative diseases. METHODS: We systematically investigated the molecular and cellular responses of the cerebellum as contributors to lentiviral infection-induced neurodegeneration, in the simian immunodeficiency virus (SIV)-infected rhesus macaque model for HIV infection and HAND. Four cohorts of animals were studied: non-infected controls, SIV-infected asymptomatic animals, and SIV-infected AIDS-diseased animals with and without brain-permeant antiretroviral treatment. The antiretroviral utilized was 6-chloro-2',3'-dideoxyguanosine (6-Cl-ddG), a CNS-permeable nucleoside reverse transcriptase inhibitor. Quantitation of granule cells and Purkinje cells, of an established biomarker of SIV infection (gp41), of microglial/monocyte/macrophage markers (IBA-1, CD68, CD163), and of the astroglial marker (GFAP) were used to reveal cell-specific cerebellar responses to lentiviral infection and antiretroviral therapy (ART). The macromolecular integrity of the blood brain barrier was tested by albumin immunohistochemistry. RESULTS: Productive CNS infection was observed in the symptomatic stage of disease, and correlated with extensive microglial/macrophage and astrocyte activation, and widespread macromolecular blood brain barrier defects. Signs of productive infection, and inflammation, were reversed upon treatment with 6-Cl-ddG, except for a residual low-grade activation of microglial cells and astrocytes. There was an extensive loss of granule cells in the SIV-infected asymptomatic cohort, which was further increased in the symptomatic stage of the disease and persisted after 6-Cl-ddG (administered after the onset of symptoms of AIDS). In the symptomatic stage, Purkinje cell density was reduced. Purkinje cell loss was likewise unaffected by 6-Cl-ddG treatment at this time. CONCLUSIONS: Our findings suggest that neurodegenerative mechanisms are triggered by SIV infection early in the disease process, i. e., preceding large-scale cerebellar productive infection and marked neuroinflammation. These affect primarily granule cells early in disease, with later involvement of Purkinje cells, indicating differential vulnerability of the two neuronal populations. The results presented here indicate a role for the cerebellum in neuro-AIDS. They also support the conclusion that, in order to attenuate the development of motor and cognitive dysfunctions in HIV-positive individuals, CNS-permeant antiretroviral therapy combined with anti-inflammatory and neuroprotective treatment is indicated even before overt signs of CNS inflammation occur.

l-DOPA-induced dyskinesia is associated with a deficient numerical downregulation of striatal tyrosine hydroxylase mRNA-expressing neurons.

l-3,4-Dihydroxyphenylalanine (l-DOPA) is the therapeutic gold standard in Parkinson's disease. However, most patients develop debilitating abnormal involuntary movements termed l-DOPA-induced dyskinesia (LID) as therapy-complicating side effects. The underlying mechanisms of LID pathogenesis are still not fully understood. Recent evidence suggests an involvement of striatal tyrosine hydroxylase (TH) protein-expressing neurons, as they are capable of endogenously producing l-DOPA and possibly dopamine. The aim of this study was to elucidate changes of TH transcription in the striatum and nucleus accumbens that occur under experimental conditions of LID. Mice with a unilateral 6-hydroxydopamine-induced lesion of the medial forebrain bundle were treated daily with l-DOPA for 15days to provoke dyskinesia. In situ hybridization analysis revealed a significant numerical decrease of TH mRNA-positive neurons in the striatum and nucleus accumbens of mice not exhibiting LID, whereas dyskinetic animals failed to show this reduction of TH transcription. Interestingly, similar changes were observed in intact non-deafferentiated striata, demonstrating an l-DOPA-responsive transcriptional TH regulation independently from nigrostriatal lesion severity. Consolidation with our previous study on TH protein level (Keber et al., 2015) impressively highlights that LID is associated with both a deficient downregulation of TH transcription and an excessive translation of TH protein in intrastriatal neurons. As TH protein levels in comparison to mRNA levels showed a stronger correlation with development and severity of LID, antidyskinetic treatment strategies should focus on translational and posttranslational modulations of TH as a promising target.