Brain microvascular smooth muscle and endothelial cells produce granulocyte macrophage colony-stimulating factor and support colony formation of granulocyte-macrophage-like cells.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a potent stimulator of macrophages and neutrophils and plays a role in inflammatory diseases. In this article, we report that mouse brain-derived microvascular smooth muscle cells (SM) and endothelial cells (En) in coculture with splenocytes support the colony proliferation of immature granulocyte-macrophage-like (GM) cells. Unstimulated SM and En cells release GM-CSF as shown by ELISA assay and SM expresses mRNA for GM-CSF by polymerase chain reaction (PCR). Stimulation of SM and En by a nonspecific activator (lipopolysaccharide) results in upregulation of GM-CSF production. GM colonies cannot be grown on cultured astrocytes or on extracellular matrix alone prepared from smooth muscle or endothelium. However, colonies form on the extracellular matrix and on astrocytes, either in the presence of SM- or En-conditioned medium or after the addition of recombinant GM-CSF. The GM cells are positive for nonspecific esterase, peroxidase, and MAC-1 markers but are negative for FC gamma receptors and for Thy 1.2, CD8, CD4, MHC class II, and Asialo GM1 markers. These observations emphasize the possibility for active participation of brain microvasculature SM and En in acute inflammatory reactions of the central nervous system.     

Whole-body imaging of sequestration of Plasmodium falciparum in the rat

The occlusion of vessels by packed Plasmodium falciparum-infected (iRBC) and uninfected erythrocytes is a characteristic postmortem finding in the microvasculature of patients with severe malaria. Here we have employed immunocompetent Sprague-Dawley rats to establish sequestration in vivo. Human iRBC cultivated in vitro and purified in a single step over a magnet were labeled with 99mtechnetium, injected into the tail vein of the rat, and monitored dynamically for adhesion in the microvasculature using whole-body imaging or imaging of the lungs subsequent to surgical removal. iRBC of different lines and clones sequester avidly in vivo while uninfected erythrocytes did not. Histological examination revealed that a multiadhesive parasite adhered in the larger microvasculature, inducing extensive intravascular changes while CD36- and chondroitin sulfate A-specific parasites predominantly sequester in capillaries, inducing no or minor pathology. Removal of the adhesive ligand Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1), preincubation of the iRBC with sera to PfEMP1 or preincubation with soluble PfEMP1-receptors prior to injection significantly reduced the sequestration. The specificity of iRBC binding to the heterologous murine receptors was confirmed in vitro, using primary rat lung endothelial cells and rat lung cryosections. In offering flow dynamics, nonmanipulated endothelial cells, and an intact immune system, we believe this syngeneic animal model to be an important complement to existing in vitro systems for the screening of vaccines and adjunct therapies aiming at the prevention and treatment of severe malaria.     

Mosaicism of the CAG repeat sequence in the Huntington disease gene in a pair of monozygotic twins

We report on a pair of monozygotic twins belonging to a family segregating Huntington disease (HD). In routine DNA analysis of blood cells, they displayed three alleles of the CAG repeat sequence in the HD gene. Two different cell lines, carrying the normal allele together with either an expanded allele with 47 CAGs or an intermediate allele with 37 CAGs, were detected in blood and buccal epithelium from both twins. To our knowledge, this is the first case described of HD gene CAG repeat length mosaicism in blood cells. Haplotype analysis established that the 37 CAG allele most likely arose by contraction of the maternal 47 CAG allele. The contraction must have taken place postzygotically, possibly at a very early stage of development, and probably before separation of the twins. One of the twins has presented symptoms of HD for 4 years; his skin fibroblasts and hair roots carried only the cell line with the 47 CAG repeat allele. The other twin, who is without symptoms at present, displayed mosaicism in skin fibroblasts and hair roots. If the proportion of the two cell lines in the brain of each twin resembles that of their hair roots (another tissue originating from the ectoderm), the mosaicism in the unaffected twin would mean that only a part of his brain cells carried the expanded allele, which could explain why he, in contrast to his brother, has no symptoms at this time.     

High-throughput single strand conformation polymorphism mutation detection by automated capillary array electrophoresis: validation of the method

Capillary array electrophoresis (CAE) is a novel technique, which allows for high throughput analysis of DNA fragments. When screening for mutations in whole populations or large patient groups it is necessary to have robust and well-characterized setups for high throughput analysis. For large-scale mutation screening, we have developed procedures for single strand conformation polymorphism (SSCP) assays using CAE (CAE-SSCP) whereby we may increase both the sensitivity and the throughput compared to conventional SSCP analysis. In this study we have validated CAE-SSCP by 1) comparing detection by slab-gel based SSCP with CAE-SSCP of mutations in the MYH7, MYL2, and MYL3 genes encoding sarcomere proteins from patients suffering from hypertrophic cardiomyopathy; and 2) by constructing a series of 185 mutants having substitution mutations, as well as insertion/deletion mutations, or some combinations of these, in different sequence contexts in four exons and different positions relative to the end of the amplicon (three from the KCNQ1 gene, encoding a cardiac potassium channel, and one from the TNNI3 gene encoding cardiac troponin I). The method identified 181 out of 185 mutations (98%), and the data suggest that the position of mutation in the fragment had no effect on the sensitivity. Analysis of the specificity of the method showed that only very few mutants could not be distinguished from each other and there were no false positives.     

Progenitor cells in liver regeneration: molecular responses controlling their activation and expansion

Although normally quiescent, the adult mammalian liver possesses a great capacity to regenerate after different types of injuries in order to restore the lost liver mass and ensure maintenance of the multiple liver functions. Major players in the regeneration process are mature residual cells, including hepatocytes, cholangiocytes and stromal cells. However, if the regenerative capacity of mature cells is impaired by liver-damaging agents, hepatic progenitor cells are activated and expand into the liver parenchyma. Upon transit amplification, the progenitor cells may generate new hepatocytes and biliary cells to restore liver homeostasis. In recent years, hepatic progenitor cells have been the subject of increasing interest due to their therapeutic potential in numerous liver diseases as alternative or supportive/complementary tools to liver transplantation. While the first investigations on hepatic progenitor cells have focused on their origin and phenotypic characterization, recent attention has focused on the influence of the hepatic microenvironment on their activation and proliferation. This microenvironment comprises the extracellular matrix, epithelial and non-epithelial resident liver cells, and recruited inflammatory cells as well as the variety of growth-modulating molecules produced and/or harboured by these elements. The cellular and molecular responses to different regenerative stimuli seem to depend on the injury inflicted and consequently on the molecular microenvironment created in the liver by a certain insult. This review will focus on molecular responses controlling activation and expansion of the hepatic progenitor cell niche, emphasizing similarities and differences in the microenvironments orchestrating regeneration by recruitment of progenitor cell populations or by replication of mature cells.     

Human-relevant near-organ neuromodulation of the immune system via the splenic nerve

Neuromodulation of immune function by stimulating the autonomic connections to the spleen has been demonstrated in rodent models. Consequently, neuroimmune modulation has been proposed as a new therapeutic strategy for the treatment of inflammatory conditions. However, demonstration of the translation of these immunomodulatory mechanisms in anatomically and physiologically relevant models is still lacking. Additionally, translational models are required to identify stimulation parameters that can be transferred to clinical applications of bioelectronic medicines. Here, we performed neuroanatomical and functional comparison of the mouse, rat, pig, and human splenic nerve using in vivo and ex vivo preparations. The pig was identified as a more suitable model of the human splenic innervation. Using functional electrophysiology, we developed a clinically relevant marker of splenic nerve engagement through stimulation-dependent reversible reduction in local blood flow. Translation of immunomodulatory mechanisms were then assessed using pig splenocytes and two models of acute inflammation in anesthetized pigs. The pig splenic nerve was shown to locally release noradrenaline upon stimulation, which was able to modulate cytokine production by pig splenocytes. Splenic nerve stimulation was found to promote cardiovascular protection as well as cytokine modulation in a high- and a low-dose lipopolysaccharide model, respectively. Importantly, splenic nerve–induced cytokine modulation was reproduced by stimulating the efferent trunk of the cervical vagus nerve. This work demonstrates that immune responses can be modulated by stimulation of spleen-targeted autonomic nerves in translational species and identifies splenic nerve stimulation parameters and biomarkers that are directly applicable to humans due to anatomical and electrophysiological similarities.

The inflammatory status of the body is monitored and regulated through the neuroimmune axis, connecting the brain to the immune system via both humoral and neural pathways (1–3). In particular, the inflammatory reflex (3) controls systemic immune responses; detection of inflammatory stimuli in the periphery is communicated to the brain that activates outflow of neural signals to promote peripheral immune responses proportional to the threat. Studies in rodent models have identified the cholinergic anti-inflammatory pathway (CAIP) as the brain’s efferent response to infection and inflammation through peripheral neurotransmitters released in lymphoid organs, mainly the spleen (4, 5). Within this pathway, the peripheral connection between the vagus nerve (VN), the splenic nerve (SpN), and its terminal release of noradrenaline (NA) into the spleen have been identified as crucial components of this neural circuit (6–8) (SI Appendix, Fig. S1A).Importantly, the CAIP can be harnessed to promote immune control. Activation of the cervical VN by electrical stimulation (vagus nerve stimulation—VNS; SI Appendix, Fig. S1A) has been shown to be effective in reducing lipopolysaccharide (LPS)-induced levels of tumor necrosis factor alpha (TNF-α) (4, 6, 7) and in preclinical rodent models of chronic inflammatory diseases (9, 10). Murine models have generally been used to demonstrate biological proof of concepts of novel neuromodulation therapies in this and other contexts. However, the development of clinical bioelectronic medicines requires the accurate estimation and validation of stimulation parameters in a histologically, surgically, and anatomically relevant model to define device and therapy requirements. The translation of stimulation parameters from rodent to human is hampered by anatomical (e.g., size of nerves), histological (e.g., number of axons, connective tissue thickness, proportion of adipose tissue), and physiological (e.g., immunological) differences. Therefore, it is suggested that the use of large animal models, human tissues, and in silico modeling are more appropriate for the optimization and scaling of human-relevant parameters (11, 12).Although early clinical feasibility studies have provided preliminary evidence of immunomodulatory effects of VNS in patients (13, 14), clear demonstration of the translation of the splenic anti-inflammatory pathway in clinically relevant species is currently lacking in the literature. The VN has a functionally and anatomically complex composition. In animals and humans, the VN contains both afferent and efferent axons of varying size (large, medium, and small) and degree of myelination (heavily myelinated, lightly myelinated, and unmyelinated axons) innervating multiple organs and muscles (15). As a consequence, currently used VNS results in activation of off-target circuits (SI Appendix, Fig. S1A) that can cause dysphonia, coughing, hoarseness, pain, and dyspnea (16–18); in some patients, these can be managed and can also improve over time (18). Further, it remains unclear which axons (efferent versus afferent, myelinated versus unmyelinated) within the VN relay immunomodulatory signals to peripheral organs (19, 20). As a result, it is difficult to optimize the stimulation parameters necessary to activate axons within the VN which carry signals to the spleen. Typically, clinical parameters are selected based on the individual patient’s tolerance of off-target effects (13, 21) without direct evidence of activation of the anti-inflammatory pathway because of a lack of an organ-specific biomarker. Since the SpN directly transmits neural signals to the spleen and is the fundamental nodal circuit in mediating the anti-inflammatory response (22), SpN stimulation (SpNS) may represent an alternative modality providing the opportunity for near-organ modulation of the immune system (SI Appendix, Fig. S1 B and C). Proof of concept experiments in rodents have shown that immune responses can indeed be modulated by stimulation of the SpN with comparable cytokine suppressive effects to VNS (7, 8, 23).Here, we anatomically, histologically, and functionally compared the mouse, rat, pig, and human SpN, demonstrating the superiority of the pig as a translational model of the human SpN. We then performed functional in vivo pig electrophysiological studies to identify organ-specific physiological biomarkers that can be used to assess nerve engagement and to refine stimulation parameters. Finally, we assessed the large animal translation of the spleen-dependent anti-inflammatory pathway in the pig using in vitro splenocyte preparations together with two in vivo models of acute inflammation.     

Attention deficit and hyperactivity disorder symptoms respond to gluten-free diet in patients with coeliac disease

Introduction: Patients with coeliac disease commonly report symptoms of ‘brain fog’. The aim of this study was to assess self-reported symptoms of impaired concentration in coeliac disease before and after treatment with gluten-free diet, compared with healthy controls and patient controls.

Methods: Patients with newly diagnosed coeliac disease were included consecutively from two out-patient clinics. The patients completed the questionnaires Adult ADHD Self-Report Scale v1.1 Symptoms Checklist (ASRS), Hospital Anxiety and Depression Scale (HADS) and Gastrointestinal Symptom Rating Scale (GSRS) prior to start of a gluten-free diet and after at least 12 months on the diet. Patients with an established diagnosis of inflammatory bowel disease served as patient controls (n?=?36). Health care personnel at Oslo University Hospital served as healthy controls (n?=?60) and filled out ASRS and HADS.

Results: A total of 31 newly diagnosed coeliac patients were included in the study. Of these, 26 patients met for follow-up and repeated the questionnaires. Prior to treatment, patients with coeliac disease had significantly higher scores than healthy controls on both the ASRS (p?=?.0014) and HADS (p=.0004). After a gluten-free diet, their scores improved and were not significantly different from healthy controls. There were no significant differences between patients with coeliac disease prior to treatment and patient controls with inflammatory bowel disease.

Conclusion: Prior to treatment, coeliac disease patients reported significantly more symptoms than healthy controls on ASRS and HADS. The differences disappeared after a minimum of 12 months on a gluten-free diet.     

Anxiety and depression among subjects attending genetic counseling for hereditary cancer

OBJECTIVES: The main aims of the study were to investigate changes in anxiety and depression over time in subjects attending genetic counseling (GC) for hereditary cancer, and secondly, to identify psychological, social, and medical variables associated with the course and outcome of anxiety and depression. METHODS: Of 275 eligible individuals, 221 consented to participate, 214 returned the baseline questionnaire, and were included in a prospective multi-center study. Questionnaires were mailed to the subjects before and after the GC. RESULTS: The mean values for anxiety and depression were quite low at all assessments. Mixed linear analyzes revealed that both anxiety and depression declined over time. Higher age, GC-related self-efficacy, and social support were associated with lower levels of anxiety. More social support, satisfaction with GC, self-rated physical function, and GC-related self-efficacy were associated with lower levels of depression. The effects of social support on both anxiety and depression had a significant interaction with time. CONCLUSION: The results support the buffer theory, which proposes that social support acts as a buffer, protecting people from the potentially pathogenic influence of stressful life events, such as GC. PRACTICE IMPLICATIONS: Subjects with less social support and less GC-related self-efficacy seem to be more vulnerable to anxiety and depression and should be offered extra attention by counselors.