Type-3 Hyaluronan Synthase Attenuates Tumor Cells Invasion in Human Mammary Parenchymal Tissues.

The microenvironment for tumor growth and developing metastasis should be essential. This study demonstrated that the hyaluronic acid synthase 3 (HAS3) protein and its enzymatic product hyaluronic acid (HA) encompassed in the subcutaneous extracellular matrix can attenuate the invasion of human breast tumor cells. Decreased HA levels in subcutaneous Has3-KO mouse tissues promoted orthotopic breast cancer (E0771) cell-derived allograft tumor growth. MDA-MB-231 cells premixed with higher concentration HA attenuate tumor growth in xenografted nude mice. Human patient-derived xenotransplantation (PDX) experiments found that HA selected the highly migratory breast cancer cells with CD44 expression accumulated in the tumor/stroma junction. In conclusion, HAS3 and HA were detected in the stroma breast tissues at a high level attenuates effects for induced breast cancer cell death, and inhibit the cancer cells invasion at the initial stage. However, the highly migratory cancer cells were resistant to the HA-mediated effects with unknown mechanisms.

Expression of cytokines in dairy cattle mammary gland parenchyma during chronic staphylococcal infection.

The study aim was to determine the expression of genes potentially related to chronic mastitis at the mRNA and protein levels, viz. chemokine C-C motif receptor 1 (CCR1), C-C motif chemokine ligand 2 (CCL2), C-C motif chemokine ligand 5 (CXCL5), tumor necrosis factor α (TNFα), interleukin 1ß (IL-1ß), interleukin 6 (IL-6), interleukin 8 (IL-8), interleukin 18 (IL-18), in bovine mammary gland parenchyma. The study examines the differences in expression of selected genes between cows with chronic mastitis caused by coagulase-positive (CoPS) or coagulase-negative staphylococci (CoNS) and those with healthy udders (H). Samples were collected from the udder quarters from 40 Polish Holstein-Friesian cows; 54 of these samples were chosen for analysis based on microbiological analysis of milk taken two days before slaughter. They were categorized into three groups: CoPS (N = 27), CoNS (N = 14) and H (N = 13). The RNA expression was analyzed by RT-qPCR and protein concentration by ELISA. No differences in the mRNA levels of seven genes (TNFα, IL-18, CCR1, IL-1ß, CCL2, IL-8, IL-6) and four proteins (TNFα, IL-18, CCR1, IL-1ß) were identified between the CoPS and H groups. Higher transcript levels of CXCL5 (p ≤ 0.05) gene were noted in CoPS than in H. Compared to H, higher concentrations of IL-8 and CXCL5 (p ≤ 0.05) were observed in CoPS (0.05 < p < 0.1) and CCL2 (0.05 < p < 0.1) in CoNS, while lower levels of Il-6 were found in CoPS. This may suggest that during chronic mastitis the organism stops producing pro-inflammatory cytokines, probably to protect the host tissues against their damage during prolonged infection.

Bcl6 controls meningeal Th17-B cell interaction in murine neuroinflammation.

Ectopic lymphoid tissue containing B cells forms in the meninges at late stages of human multiple sclerosis (MS) and when neuroinflammation is induced by interleukin (IL)-17 producing T helper (Th17) cells in rodents. B cell differentiation and the subsequent release of class-switched immunoglobulins have been speculated to occur in the meninges, but the exact cellular composition and underlying mechanisms of meningeal-dominated inflammation remain unknown. Here, we performed in-depth characterization of meningeal versus parenchymal Th17-induced rodent neuroinflammation. The most pronounced cellular and transcriptional differences between these compartments was the localization of B cells exhibiting a follicular phenotype exclusively to the meninges. Correspondingly, meningeal but not parenchymal Th17 cells acquired a B cell-supporting phenotype and resided in close contact with B cells. This preferential B cell tropism for the meninges and the formation of meningeal ectopic lymphoid tissue was partially dependent on the expression of the transcription factor Bcl6 in Th17 cells that is required in other T cell lineages to induce isotype class switching in B cells. A function of Bcl6 in Th17 cells was only detected in vivo and was reflected by the induction of B cell-supporting cytokines, the appearance of follicular B cells in the meninges, and of immunoglobulin class switching in the cerebrospinal fluid. We thus identify the induction of a B cell-supporting meningeal microenvironment by Bcl6 in Th17 cells as a mechanism controlling compartment specificity in neuroinflammation.

Metabolic profiles of human brain parenchyma and glioma for rapid tissue diagnosis by targeted desorption electrospray ionization mass spectrometry.

Desorption electrospray ionization mass spectrometry (DESI-MS) is well suited for intraoperative tissue analysis since it requires little sample preparation and offers rapid and sensitive molecular diagnostics. Currently, intraoperative assessment of the tumor cell percentage of glioma biopsies can be made by measuring a single metabolite, N-acetylaspartate (NAA). The inclusion of additional biomarkers will likely improve the accuracy when distinguishing brain parenchyma from glioma by DESI-MS. To explore this possibility, mass spectra were recorded for extracts from 32 unmodified human brain samples with known pathology. Statistical analysis of data obtained from full-scan and multiple reaction monitoring (MRM) profiles identified discriminatory metabolites, namely gamma-aminobutyric acid (GABA), creatine, glutamic acid, carnitine, and hexane-1,2,3,4,5,6-hexol (abbreviated as hexol), as well as the established biomarker NAA. Brain parenchyma was readily differentiated from glioma based on these metabolites as measured both in full-scan mass spectra and by the intensities of their characteristic MRM transitions. New DESI-MS methods (5 min acquisition using full scans and MS/MS), developed to measure ion abundance ratios among these metabolites, were tested using smears of 29 brain samples. Ion abundance ratios based on signals for GABA, creatine, carnitine, and hexol all had sensitivities > 90%, specificities > 80%, and accuracies > 85%. Prospectively, the implementation of diagnostic ion abundance ratios should strengthen the discriminatory power of individual biomarkers and enhance method robustness against signal fluctuations, resulting in an improved DESI-MS method of glioma diagnosis.

Aging induces abnormal accumulation of Aß in extracellular vesicle and/or intraluminal membrane vesicle-rich fractions in nonhuman primate brain.

Aß metabolism in the brain is mediated by endocytosis, one part of the intracellular membrane trafficking system. We previously showed that aging attenuates the interaction of dynein with dynactin, which disrupts the endosomal/lysosomal trafficking pathway involved in Aß metabolism, resulting in intracellular accumulation of Aß. Several studies have shown that in Alzheimer's disease (AD), intraneuronal accumulation of Aß precedes extracellular Aß depositions. However, it is unclear what accounts for this transition from intracellular to extracellular depositions. Accumulating evidence suggest that autophagy has an important role in AD pathology, and we observed that autophagy-related protein levels began to decrease before amyloid plaque formation in cynomolgus monkey brains. Surprisingly, experimental induction of autophagosome formation in Neuro2a cells significantly increased intracellular Aß and decreased extracellular release of Aß, accompanied by the prominent reduction of extracellular vesicle (EV) secretion. RNAi study confirmed that EV secretion affected intracellular and extracellular Aß levels, and siRNA-induced downregulation of autophagosome formation enhanced EV secretion to ameliorate intracellular Aß accumulation induced by dynein knockdown. In aged cynomolgus monkeys, Aß levels in EV/intraluminal membrane vesicle (ILV)-rich fractions isolated from temporal lobe parenchyma were drastically increased. Moreover, EV/ILV marker proteins overlapped spatially with amyloid plaques. These findings suggest that EV would be an important carrier of Aß in brain and abnormal accumulation of Aß in EVs/ILVs may be involved in the transition of age-dependent Aß pathology.

EGFR and KRAS Mutations in Lung Parenchyma of Subjects With EGFR/KRAS Wild-Type Lung Adenocarcinoma.

The acquisition of driver mutations in non-tumoral cells appears to be very important during the carcinogenesis of adenocarcinoma (ADC). Recent studies suggest that cancer-related mutations may not necessarily be present only in malignant cells, but also in histologically "healthy cells". Objective: to demonstrate the presence of EGFR or KRAS mutations in non-tumoral lung cells in subjects with ADC and negative mutational status. Results: mutations in EGFR or KRAS oncogenes were identified in the normal lung in 9.7% of the subjects. Exon 21 substitution L858R in EGFR was detected in two cases while the exon 19 deletion E746-A750 in the EGFR, the G12C and G12D substitutions in the KRAS were detected once. One patient presented three different mutations in the normal lung parenchyma (EGFR_L858R, KRAS_G12C and KRAS_G12D). The negative-mutation status of the tumor and the mutations detected in the "normal lung" were confirmed using highly sensitive and specific TaqMan PCR (CAST-PCR). No differences were found in terms of progression, progression-free survival or overall survival during the 18 months follow-up. Conclusions: These results confirm the presence of driver mutations in the histologically normal lung parenchyma cells in the absence of mutations coexisting with the primary tumor.

Types of Parenchymal Changes Diagnosed on DMSA Scans of Kidneys Affected by Different Grades of Vesicoureteral Reflux.

BACKGROUND Renal parenchymal damage and scarring usually is associated with urinary tract infection (UTI), whereas the impact of vesicoureteral reflux (VUR) on the kidneys is unclear. We aimed to compare kidneys with all grades of VUR (grades Io-V) and those without VUR by using direct radionuclide cystography, voiding cystourethrography, and findings from 99mTc-DMSA scintigraphy (DMSA scan). MATERIAL AND METHODS The present analysis included 253 renal ureteral units (RUU) from 129 children with VUR and recurrent UTI and children with a single febrile UTI associated with abnormal ultrasonographic findings. The 6 grades of VUR (Io, I, II, III, IV, and V) and 35 RUUs without VUR were divided into 4 groups: 1. Non-dilated VUR (grades Io-II); 2. Mildly dilated VUR (grade III); 3. Dilated VUR (grades IV-V); and 4. The control group. RESULTS DMSA scanning showed significant differences between the groups with non-dilated VUR, grade III VUR, grades IV-V VUR, and the control group in kidney width (χ²=30.5; P<0.001); position and shape (χ²=30.6; P<0.001); intensity of activity (χ²=38.1; P<0.001); distribution of activity (χ²=34.5; P<0.001); and existence of scars (χ²=16; P<0.001). The probability of abnormalities on DMSA scans increased with the VUR grade. However, inside the groups of dilated and non-dilated VUR we found no significant statistical differences between those characteristics. CONCLUSIONS Our results indicate that kidneys without VUR or with non-dilated lateral VUR and dilated VUR on the contralateral side represent 2 different categories of parenchymal changes.

CNS macrophages differentially rely on an intronic Csf1r enhancer for their development.

The central nervous system hosts parenchymal macrophages, known as microglia, and non-parenchymal macrophages, collectively termed border-associated macrophages (BAMs). Microglia, but not BAMs, were reported to be absent in mice lacking a conserved Csf1r enhancer: the fms-intronic regulatory element (FIRE). However, it is unknown whether FIRE deficiency also impacts BAM arrival and/or maintenance. Here, we show that macrophages in the ventricular system of the brain, including Kolmer's epiplexus macrophages, are absent in Csf1rΔFIRE/ΔFIRE mice. Stromal choroid plexus BAMs are also considerably reduced. During normal development, we demonstrate that intracerebroventricular macrophages arrive from embryonic day 10.5, and can traverse ventricular walls in embryonic slice cultures. In Csf1rΔFIRE/ΔFIRE embryos, the arrival of both primitive microglia and intracerebroventricular macrophages was eliminated, whereas the arrival of cephalic mesenchyme and stromal choroid plexus BAMs was only partially restricted. Our results provide new insights into the development and regulation of different CNS macrophage populations.

Extraparenchymal human neurocysticercosis induces autoantibodies against brain tubulin and MOG35-55 in cerebral spinal fluid.

Neurocysticercosis (NC) presents two broad clinical entities: extraparenchymal (EP-NC) and parenchymal (P-NC). Using ELISA methodology, we demonstrate autoantibodies to tubulin and the Major oligodendrocyte glycoprotein (MOG) in the CSF of most, but not all, EP-NC samples. Levels of these autoantibodies were considerably reduced or absent in the P-NC samples. There was a striking correlation between levels of anti-tubulin and anti-MOG, and the significant correlation between the levels of autoantibodies and cellularity in the CSF, suggests that stimulation of the autoantibody response may be a function of cerebral inflammation. A hypothetical model to describe the pathogenesis of EP-NC is presented.

Anti-brain protein autoantibodies are detectable in extraparenchymal but not parenchymal neurocysticercosis.

Neurocysticercosis (NC) presents a spectrum of clinical manifestations, with two broad clinical entities based on the central nervous system location of the parasite: extraparenchymal (EP-NC) and parenchymal (P-NC). In this work, using quantitative immunoblot methodology, we demonstrate the presence of autoantibodies to brain proteins in CSF from EP-NC, but not P-NC, patients. There was striking correlation between the level of autoantibodies and the levels of the secreted metacestode glycoprotein HP-10, suggesting that the level of stimulation of the autoantibody response may be a function of the number of viable parasites. Nine corresponding proteins autoantigens were provisionally identified by mass spectroscopy.

Glioblastoma Exhibits Inter-Individual Heterogeneity of TSPO and LAT1 Expression in Neoplastic and Parenchymal Cells.

Molecular imaging is essential for diagnosis and treatment planning for glioblastoma patients. Positron emission tomography (PET) with tracers for the detection of the solute carrier family 7 member 5 (SLC7A5; also known as the amino acid transporter light chain L system, LAT1) and for the mitochondrial translocator protein (TSPO) is successfully used to provide additional information on tumor volume and prognosis. The current approaches for TSPO-PET and the visualization of tracer ([18F] Fluoroethyltyrosine, FET) uptake by LAT1 (FET-PET) do not yet exploit the full diagnostic potential of these molecular imaging techniques. Therefore, we investigated the expression of TSPO and LAT1 in patient glioblastoma (GBM) samples, as well as in various GBM mouse models representing patient GBMs of different genetic subtypes. By immunohistochemistry, we found that TSPO and LAT1 are upregulated in human GBM samples compared to normal brain tissue. Next, we orthotopically implanted patient-derived GBM cells, as well as genetically engineered murine GBM cells, representing different genetic subtypes of the disease. To determine TSPO and LAT1 expression, we performed immunofluorescence staining. We found that both TSPO and LAT1 expression was increased in tumor regions of the implanted human or murine GBM cells when compared to the neighboring mouse brain tissue. While LAT1 was largely restricted to tumor cells, we found that TSPO was also expressed by microglia, tumor-associated macrophages, endothelial cells, and pericytes. The Cancer Genome Atlas (TCGA)-data analysis corroborates the upregulation of TSPO in a bigger cohort of GBM patient samples compared to tumor-free brain tissue. In addition, AIF1 (the gene encoding for the myeloid cell marker Iba1) was also upregulated in GBM compared to the control. Interestingly, TSPO, as well as AIF1, showed significantly different expression levels depending on the GBM genetic subtype, with the highest expression being exhibited in the mesenchymal subtype. High TSPO and AIF1 expression also correlated with a significant decrease in patient survival compared to low expression. In line with this finding, the expression levels for TSPO and AIF1 were also significantly higher in (isocitrate-dehydrogenase wild-type) IDHWT compared to IDH mutant (IDHMUT) GBM. LAT1 expression, on the other hand, was not different among the individual GBM subtypes. Therefore, we could conclude that FET- and TSPO-PET confer different information on pathological features based on different genetic GBM subtypes and may thus help in planning individualized strategies for brain tumor therapy in the future. A combination of TSPO-PET and FET-PET could be a promising way to visualize tumor-associated myeloid cells and select patients for treatment strategies targeting the myeloid compartment.

Comparative analyses of long non-coding RNA profiles in vivo in cystic fibrosis lung airway and parenchyma tissues.

BACKGROUND: Recent advances in the functional analyses of endogenous non-coding RNA (ncRNA) molecules, including long non-coding RNAs (LncRNAs), have provided a new perspective on the crucial roles of RNA in gene regulation. Consequently, LncRNA deregulation is a key factor in various diseases, including pulmonary disorders like Cystic Fibrosis (CF). CF is the most common life limiting recessive disease in the U.S., and is due to mutations in the CFTR gene. CF mutations, of which the most common is F508del-CFTR, prevents correct folding, trafficking and function of the mutant CFTR protein and is further manifested by the hyper-expression of pro-inflammatory cytokines and chemokines into the airway lumen leading to bronchiectasis and culminating in lung destruction. METHODS: Here we report a distinct LncRNA signature and corresponding mRNAs that distinguishes CF lung (airway and parenchyma) tissues from matched non-CF controls (n = 4 each group), generated by microarray specific for LncRNAs which includes corresponding mRNA expressions. In silico analyses of the cellular processes that are impacted by these LncRNAs was performed using Gene Ontology (GO). A selected subset of LncRNAs were validated by quantitative real-time PCR. RESULTS: We have identified 636 LncRNAs differentially expressed in CF airway epithelium and 1974 in CF lung parenchyma compared to matched non-CF controls (fold change ≥2, p < 0.05), majority of which (> 50%) are intergenic. Interestingly, 15 of these differentially expressed LncRNAs and 9 coding mRNAs are common to airway and parenchyma tissues. GO analyses indicates that signaling pathways and cell membrane functions are significantly affected by the alteration in LncRNA expressions in CF lung tissues. Seven of the differentially expressed LncRNAs, exhibit similar expression trends in CFBE41o- compared to control cells. CONCLUSION: Understanding the mechanisms by which these LncRNAs regulate CF disease phenotype will help develop novel therapeutic targets for CF and related pulmonary diseases, such as COPD and Asthma.

Classification of Background Parenchymal Uptake on Molecular Breast Imaging Using a Convolutional Neural Network.

PURPOSE: Background parenchymal uptake (BPU), which describes the level of radiotracer uptake in normal fibroglandular tissue on molecular breast imaging (MBI), has been identified as a breast cancer risk factor. Our objective was to develop and validate a deep learning model using image convolution to automatically categorize BPU on MBI. METHODS: MBI examinations obtained for clinical and research purposes from 2004 to 2015 were reviewed to classify the BPU pattern using a standardized five-category scale. Two expert radiologists provided interpretations that were used as the reference standard for modeling. The modeling consisted of training and validating a convolutional neural network to predict BPU. Model performance was summarized in data reserved to test the performance of the algorithm at the per-image and per-breast levels. RESULTS: Training was performed on 24,639 images from 3,133 unique patients. The model performance on the withheld testing data (6,172 images; 786 patients) was evaluated. Using direct matching on the predicted classification resulted in an accuracy of 69.4% (95% CI, 67.4% to 71.3%), and if prediction within one category was considered, accuracy increased to 96.0% (95% CI, 95.2% to 96.7%). When considering the breast-level prediction of BPU, the accuracy remained strong, with 70.3% (95% CI, 68.0% to 72.6%) and 96.2% (95% CI, 95.3% to 97.2%) for the direct match and allowance for one category, respectively. CONCLUSION: BPU provided a robust target for training a convolutional neural network. A validated computer algorithm will allow for objective, reproducible encoding of BPU to foster its integration into risk-stratification algorithms.

Relevance of Autophagy in Parenchymal and Non-Parenchymal Liver Cells for Health and Disease.

Autophagy is a highly conserved intracellular process for the ordered degradation and recycling of cellular components in lysosomes. In the liver, parenchymal cells (i.e., mainly hepatocytes) utilize autophagy to provide amino acids, glucose, and free fatty acids as sources of energy and biosynthesis functions, but also for recycling and controlling organelles such as mitochondria. Non-parenchymal cells of the liver, including endothelial cells, macrophages (Kupffer cells), and hepatic stellate cells (HSC), also employ autophagy, either for maintaining cellular homeostasis (macrophages, endothelium) or for providing energy for their activation (stellate cells). In hepatocytes, autophagy contributes to essential homeostatic functions (e.g., gluconeogenesis, glycogenolysis, fatty acid oxidation), but is also implicated in diseases. For instance, storage disorders (alpha 1 antitrypsin deficiency, Wilson's disease), metabolic (non-alcoholic steatohepatitis, NASH), and toxic (alcohol) liver diseases may benefit from augmenting autophagy in hepatocytes. In hepatic fibrosis, autophagy has been implicated in the fibrogenic activation of HSC to collagen-producing myofibroblasts. In hepatocellular carcinoma (HCC), autophagy may contribute to tumor surveillance as well as invasiveness, indicating a dual and stage-dependent function in cancer. As many drugs directly or indirectly modulate autophagy, it is intriguing to investigate autophagy-targeting, possibly even cell type-directed strategies for the treatment of hereditary liver diseases, NASH, fibrosis, and HCC.

Vesicular acetylcholine transport deficiency potentiates some inflammatory responses induced by diesel exhaust particles.

Endogenous acetylcholine (ACh), which depends of the levels of vesicular ACh transport (VAChT) to be released, is the central mediator of the cholinergic anti-inflammatory system. ACh controls the release of cytokine in different models of inflammation. Diesel exhaust particles (DEP) are one of the major environmental pollutants produced in large quantity by automotive engines in urban center. DEP bind the lung parenchyma and induce inflammation. We evaluated whether cholinergic dysfunction worsens DEP-induced lung inflammation. Male mice with decreased ACh release due to reduced expression of VAChT (VAChT-KD mice) were submitted to DEP exposure for 30 days (3 mg/mL of DEP, once a day, five days a week) or saline. Pulmonary function and inflammation as well as extracellular matrix fiber deposition were evaluated. Additionally, airway and nasal epithelial mucus production were quantified. We found that DEP instillation worsened lung function and increased lung inflammation. Higher levels of mononuclear cells were observed in the peripheral blood of both wild-type (WT) and VAChT-KD mice. Also, both wild-type (WT) and VAChT-KD mice showed an increase in macrophages in bronchoalveolar lavage fluid (BALF) as well as increased expression of IL-4, IL-6, IL-13, TNF-α, and NF-κB in lung cells. The collagen fiber content in alveolar septa was also increased in both genotypes. On the other hand, we observed that granulocytes were increased only in VAChT-KD peripheral blood. Likewise, increased BALF lymphocytes and neutrophils as well as increased elastic fibers in alveolar septa, airway neutral mucus, and nasal epithelia acid mucus were observed only in VAChT-KD mice. The cytokines IL-4 and TNF-α were also higher in VAChT-KD mice compared with WT mice. In conclusion, decreased ability to release ACh exacerbates some of the lung alterations induced by DEP in mice, suggesting that VAChT-KD animals are more vulnerable to the effects of DEP in the lung.

Pretreatment 18F-fluorodeoxyglucose Uptake in the Lung Parenchyma Predicts Poor Survival After Stereotactic Body Radiation Therapy in Patients With Stage I Non-Small Cell Lung Cancer.

PURPOSE: In this study, we aimed to evaluate the prognostic value of fluorodeoxyglucose uptake in the lung parenchyma and the presence of subclinical interstitial lung disease on computed tomography as predictive factors for survival following stereotactic body radiation therapy in patients with stage I non-small cell lung cancer. METHODS: We retrospectively evaluated 125 patients with stage I non-small cell lung cancer who underwent stereotactic body radiation therapy at our institute between December 2005 and March 2013 for various demographic and clinical parameters. The fluorodeoxyglucose uptake in the lung parenchyma corrected with computed tomography value (tissue fraction-corrected standardized uptake value) was quantified using fluorodeoxyglucose-positron emission tomography/computed tomography before the therapy. Additionally, the radiological findings of interstitial lung disease on computed tomography were evaluated. The prognostic analyses were performed using the Kaplan-Meier analysis and Cox proportional hazards regression model for univariate and multivariate analyses. RESULTS: The median follow-up period was 39 months. The 3-year overall survival rate was 67.9%, and the 3-year progression-free survival rate was 52.0%. The multivariate analysis indicated that the tissue fraction-corrected standardized uptake value was correlated with the patients' overall survival ( P = .027, hazard ratio: 2.694, 95% confidence interval: 1.109-8.057). The presence of subclinical interstitial lung disease showed no correlation with the overall survival ( P = .535, hazard ratio: 1.256, 95% confidence interval: 0.592-2.473). CONCLUSION: The results indicated that fluorodeoxyglucose uptake in the lung parenchyma, expressed as the tissue fraction-corrected standardized uptake value, was an independent prognostic factor in patients with stage I non-small cell lung cancer who have received stereotactic body radiation therapy.

Physiological Uptake of F18-FDG in breast parenchyma.

Increased F18-FDG uptake is on PET-CT images should always be assessed carefully for physiological and pathological causes. Breast uptake may be focal or diffuse. Although propensity of tumours increase in focal uptake; diffuse involvement may be seen in lymphoma and some types of breast cancer. Frequently, diffuse breast uptake is non-pathologic due to infection, physiological uptake or lactation. We describe the case of a 27-years old female who underwent 18F FDGPET-CT scan for staging workup of diffuse large B-cell lymphoma (DLBCL). The scan demonstrated bilateral F18-FDG breast uptake, due to ongoing lactation.

Mutant LRRK2 mediates peripheral and central immune responses leading to neurodegeneration in vivo.

Missense mutations in the leucine rich repeat kinase 2 (LRRK2) gene result in late-onset Parkinson's disease. The incomplete penetrance of LRRK2 mutations in humans and LRRK2 murine models of Parkinson's disease suggests that the disease may result from a complex interplay of genetic predispositions and persistent exogenous insults. Since neuroinflammation is commonly associated with the pathogenesis of Parkinson's disease, we examine a potential role of mutant LRRK2 in regulation of the immune response and inflammatory signalling in vivo. Here, we show that mice overexpressing human pathogenic LRRK2 mutations, but not wild-type mice or mice overexpressing human wild-type LRRK2 exhibit long-term lipopolysaccharide-induced nigral neuronal loss. This neurodegeneration is accompanied by an exacerbated neuroinflammation in the brain. The increased immune response in the brain of mutant mice subsequently has an effect on neurons by inducing intraneuronal LRRK2 upregulation. However, the enhanced neuroinflammation is unlikely to be triggered by dysfunctional microglia or infiltrated T cells and/or monocytes, but by peripheral circulating inflammatory molecules. Analysis of cytokine kinetics and inflammatory pathways in the peripheral immune cells demonstrates that LRRK2 mutation alters type II interferon immune response, suggesting that this increased neuroinflammatory response may arise outside the central nervous system. Overall, this study suggests that peripheral immune signalling plays an unexpected-but important-role in the regulation of neurodegeneration in LRRK2-associated Parkinson's disease, and provides new targets for interfering with the onset and progression of the disease.

Magnetic resonance imaging provides evidence of glymphatic drainage from human brain to cervical lymph nodes.

Pre-clinical research in rodents provides evidence that the central nervous system (CNS) has functional lymphatic vessels. In-vivo observations in humans, however, are not demonstrated. We here show data on CNS lymphatic drainage to cervical lymph nodes in-vivo by magnetic resonance imaging (MRI) enhanced with an intrathecal contrast agent as a cerebrospinal fluid (CSF) tracer. Standardized MRI of the intracranial compartment and the neck were acquired before and up to 24-48 hours following intrathecal contrast agent administration in 19 individuals. Contrast enhancement was radiologically confirmed by signal changes in CSF nearby inferior frontal gyrus, brain parenchyma of inferior frontal gyrus, parahippocampal gyrus, thalamus and pons, and parenchyma of cervical lymph node, and with sagittal sinus and neck muscle serving as reference tissue for cranial and neck MRI acquisitions, respectively. Time series of changes in signal intensity shows that contrast enhancement within CSF precedes glymphatic enhancement and peaks at 4-6 hours following intrathecal injection. Cervical lymph node enhancement coincides in time with peak glymphatic enhancement, with peak after 24 hours. Our findings provide in-vivo evidence of CSF tracer drainage to cervical lymph nodes in humans. The time course of lymph node enhancement coincided with brain glymphatic enhancement rather than with CSF enhancement.