Tenascin-C Orchestrates Glioblastoma Angiogenesis by Modulation of Pro- and Anti-angiogenic Signaling.

High expression of the extracellular matrix component tenascin-C in the tumor microenvironment correlates with decreased patient survival. Tenascin-C promotes cancer progression and a disrupted tumor vasculature through an unclear mechanism. Here, we examine the angiomodulatory role of tenascin-C. We find that direct contact of endothelial cells with tenascin-C disrupts actin polymerization, resulting in cytoplasmic retention of the transcriptional coactivator YAP. Tenascin-C also downregulates YAP pro-angiogenic target genes, thus reducing endothelial cell survival, proliferation, and tubulogenesis. Glioblastoma cells exposed to tenascin-C secrete pro-angiogenic factors that promote endothelial cell survival and tubulogenesis. Proteomic analysis of their secretome reveals a signature, including ephrin-B2, that predicts decreased survival of glioma patients. We find that ephrin-B2 is an important pro-angiogenic tenascin-C effector. Thus, we demonstrate dual activities for tenascin-C in glioblastoma angiogenesis and uncover potential targeting and prediction opportunities.

Clinical impact of the 2010-2012 low-end shift of high-sensitivity cardiac troponin T.

BACKGROUND: The clinical implications of the 2010-2012 low-end shift of high-sensitivity cardiac troponin T (hs-cTnT) regarding possible misdiagnosis of acute myocardial infarction are largely unknown. METHODS: We aimed to quantify the impact of the 2010-2012 low-end shift and adjustment issue in 857 patients presenting to the emergency department with suspected acute myocardial infarction by comparing measurements performed with affected 2010-2012 lots with recalculated 2010-2012 values using a linear regression formula (provided by the manufacturer) and the corrected assay (re-measured in 2013). The final diagnosis was adjudicated by two independent cardiologists using all information including coronary angiography, echocardiography and serial hs-cTnT levels (with the corrected 2013 assay). RESULTS: Acute myocardial infarction was the adjudicated diagnosis in 195 patients (22.7%). Median hs-TnT values were 8.5 ng/l for affected lots, 11.1 ng/l with recalculated and 10 ng/l with the corrected assay (P<0.001 for all comparisons). Spearman correlation coefficient was 0.937 (<0.001) for correct and affected respective correct and recalculated values. The Cusum test indicated significant deviation from linearity (P<0.01) for both correlations. Deviations nearly exclusively affected hs-cTnT levels below the 99th percentile (14 ng/L). Among the 195 patients with an adjudicated diagnosis of acute myocardial infarction, no patient was misclassified using affected lots if using conventional serial sampling. In contrast, misdiagnosis of acute myocardial infarction was significantly increased by affected lots if applying the novel ESC 0 h/1 h algorithm for the early rule-out of acute myocardial infarction (negative predictive value with affected lots 97.7% versus 99.7% with corrected lots). CONCLUSION: The 2010-2012 hs-cTnT low-end shift affected nearly exclusively levels below the 99th percentile cut-off. While it did not affect the diagnosis of acute myocardial infarction when using conventional serial sampling as done in 2010-2012, it would impact on new early rule-out strategies using very low levels of hs-cTnT such as the ESC 0 h/1 h algorithm. CLINICAL TRIALS REGISTRATION: NCT0047058, NCT00470587.

Dopaminergic Modulation of Cognitive Preparation for Overt Reading: Evidence from the Study of Genetic Polymorphisms.

Choosing and implementing the rules for contextually adequate behavior depends on frontostriatal interactions. Observations in Parkinson's disease and pharmacological manipulations of dopamine transmission suggest that these corticobasal loops are modulated by dopamine. To determine, therefore, the physiological contributions of dopamine to task-rule-related processing, we performed a cue-target fMRI reading paradigm in 71 healthy participants and investigated the effects of COMT Val158Met, DAT1 VNTR 9/10, and DRD2/ANKK1 polymorphisms. The DRD2/ANKK1 polymorphism did not affect results. Intermediate prefrontal dopamine concentrations in COMT Val158Met heterozygotes facilitated preparatory interactions between the mesial prefrontal cortex and the left striatum during preparation for overt reading. To our knowledge, this is the first report of an inverted U-shaped curve modulation of cognition-related brain activity by prefrontal dopamine levels. In contrast, a linear effect of COMT Val158Met and DAT1 VNTR 9/10 polymorphisms on preparatory activity in the left inferior frontal gyrus pointed to a negative interaction between tonic lateral prefrontal and phasic subcortical dopamine. The COMT Val158Met polymorphism affected also feedforward and feedback processing in the sensorimotor speech system. Our results suggest that dopamine modulates corticobasal interactions on both the cortical and subcortical level but differently depending on the specific cognitive subprocesses involved.

Misdiagnosis of Myocardial Infarction Related to Limitations of the Current Regulatory Approach to Define Clinical Decision Values for Cardiac Troponin.

BACKGROUND: Misdiagnosis of acute myocardial infarction (AMI) may significantly harm patients and may result from inappropriate clinical decision values (CDVs) for cardiac troponin (cTn) owing to limitations in the current regulatory process. METHODS AND RESULTS: In an international, prospective, multicenter study, we quantified the incidence of inconsistencies in the diagnosis of AMI using fully characterized and clinically available high-sensitivity (hs) cTn assays (hs-cTnI, Abbott; hs-cTnT, Roche) among 2300 consecutive patients with suspected AMI. We hypothesized that the approved CDVs for the 2 assays are not biologically equivalent and might therefore contribute to inconsistencies in the diagnosis of AMI. Findings were validated by use of sex-specific CDVs and parallel measurements of other hs-cTnI assays. AMI was the adjudicated diagnosis in 473 patients (21%). Among these, 86 patients (18.2%) had inconsistent diagnoses when the approved uniform CDV was used. When sex-specific CDVs were used, 14.1% of female and 22.7% of male AMI patients had inconsistent diagnoses. Using biologically equivalent CDV reduced inconsistencies to 10% (P<0.001). These findings were confirmed with parallel measurements of other hs-cTn assays. The incidence of inconsistencies was only 7.0% for assays with CDVs that were nearly biologically equivalent. Patients with inconsistent AMI had long-term mortality comparable to that of patients with consistent diagnoses (P=NS) and a trend toward higher long-term mortality than patients diagnosed with unstable angina (P=0.05). CONCLUSIONS: Currently approved CDVs are not biologically equivalent and contribute to major inconsistencies in the diagnosis of AMI. One of 5 AMI patients will receive a diagnosis other than AMI if managed with the alternative hs-cTn assay. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00470587.

Spatial organization of the tenascin-C microenvironment in experimental and human cancer.

The extracellular matrix (ECM) molecule tenascin-C (TNC) promotes tumor progression. This has recently been demonstrated in the stochastic murine RIP1-Tag2 insulinoma model, engineered to either express TNC abundantly or to be devoid of TNC. However, our knowledge about organization of the TNC microenvironment is scant. Here we determined the spatial distribution of TNC together with other ECM molecules in murine RIP1-Tag2 insulinoma and human cancer tissue (insulinoma and colorectal carcinoma). We found that TNC is organized in matrix tracks together with other ECM molecules of the AngioMatrix signature, a previously described gene expression profile that characterizes the angiogenic switch. Moreover, stromal cells including endothelial cells, fibroblasts and leukocytes were enriched in the TNC tracks. Thus, TNC tracks may provide niches for stromal cells and regulate their behavior. Given similarities of TNC rich niches for stromal cells in human insulinoma and colon cancer, we propose that the RIP1-Tag2 model may be useful for providing insights into the contribution of the tumor stroma specific ECM as promoter of cancer progression.

AngioMatrix, a signature of the tumor angiogenic switch-specific matrisome, correlates with poor prognosis for glioma and colorectal cancer patients.

Angiogenesis represents a rate-limiting step during tumor progression. Targeting angiogenesis is already applied in cancer treatment, yet limits of anti-angiogenic therapies have emerged, notably because tumors adapt and recur after treatment. Therefore, there is a strong need to better understand the molecular and cellular mechanisms underlying tumor angiogenesis. Using the RIP1-Tag2 transgenic murine model, we identified 298 genes that are deregulated during the angiogenic switch, revealing an ingression/expansion of specific stromal cell types including endothelial cells and pericytes, but also macrophages and perivascular mesenchymal cells. Canonical TGF-ß signaling is up-regulated during the angiogenic switch, especially in tumor-associated macrophages and fibroblasts. The matrisome, comprising extracellular matrix (ECM) and ECM-associated molecules, is significantly enriched, which allowed us to define the AngioMatrix signature as the 110 matrisomal genes induced during the RIP1-Tag2 angiogenic switch. Several AngioMatrix molecules were validated at expression level. Ablation of tenascin-C, one of the most highly induced ECM molecules during the switch, resulted in reduced angiogenesis confirming its important role. In human glioma and colorectal samples, the AngioMatrix signature correlates with the expression of endothelial cell markers, is increased with tumor progression and finally correlates with poor prognosis demonstrating its diagnostic and therapeutic potential.

The laminin response in inflammatory bowel disease: protection or malignancy?

Laminins (LM), basement membrane molecules and mediators of epithelial-stromal communication, are crucial in tissue homeostasis. Inflammatory Bowel Diseases (IBD) are multifactorial pathologies where the microenvironment and in particular LM play an important yet poorly understood role in tissue maintenance, and in cancer progression which represents an inherent risk of IBD. Here we showed first that in human IBD colonic samples and in murine colitis the LMα1 and LMα5 chains are specifically and ectopically overexpressed with a concomitant nuclear p53 accumulation. Linked to this observation, we provided a mechanism showing that p53 induces LMα1 expression at the promoter level by ChIP analysis and this was confirmed by knockdown in cell transfection experiments. To mimic the human disease, we induced colitis and colitis-associated cancer by chemical treatment (DSS) combined or not with a carcinogen (AOM) in transgenic mice overexpressing LMα1 or LMα5 specifically in the intestine. We demonstrated that high LMα1 or LMα5 expression decreased susceptibility towards experimentally DSS-induced colon inflammation as assessed by histological scoring and decrease of pro-inflammatory cytokines. Yet in a pro-oncogenic context, we showed that LM would favor tumorigenesis as revealed by enhanced tumor lesion formation in both LM transgenic mice. Altogether, our results showed that nuclear p53 and associated overexpression of LMα1 and LMα5 protect tissue from inflammation. But in a mutation setting, the same LM molecules favor progression of IBD into colitis-associated cancer. Our transgenic mice represent attractive new models to acquire knowledge about the paradoxical effect of LM that mediate either tissue reparation or cancer according to the microenvironment. In the early phases of IBD, reinforcing basement membrane stability/organization could be a promising therapeutic approach.

Prevalence, characteristics and outcome of non-cardiac chest pain and elevated copeptin levels.

OBJECTIVE: Copeptin, a quantitative marker of endogenous stress, seems to provide incremental value in addition to cardiac troponin in the early rule-out of acute myocardial infarction (AMI). Prevalence, characteristics and outcome of acute chest pain patients with causes other than AMI and elevated copeptin are poorly understood. METHODS: A total of 984 consecutive patients with non-cardiac chest pain were selected from a prospective multicentre study of acute chest pain patients presenting to the emergency department. Levels of copeptin were determined in a blinded fashion and considered elevated if above 13 pmol/L (the 97,5th centile of healthy individuals). The final diagnosis was adjudicated by two independent cardiologists. Median duration of follow-up was 756 days. RESULTS: Elevated copeptin levels were seen in 215 patients (22%). In comparison to patients with normal copeptin levels, patients with elevated levels were older, had more pre-existing cardiac and non-cardiac disorders, more silent cardiomyocyte injury and increased haemodynamic stress as quantified by levels of high-sensitivity cardiac troponin T (9.6 ng/L (3.6-18.3) vs 5.8 ng/L (2.9-9.4)) and B-type natriuretic peptide (75 ng/L (37-187) vs 35 ng/L (15-77)) (both p<0.001), more electrocardiographic abnormalities, more often an adjudicated diagnosis of gastroesophageal reflux or bronchitis/pneumonia and higher 2- year mortality (HR 2.9, 95% CI 1.5  to 5.7). The increased mortality rate seemed to be largely explained by age and comorbidities. CONCLUSIONS: Elevated levels of copeptin are present in about one in five patients with non-cardiac chest pain and are associated with aging, cardiac and non-cardiac comorbidities as well as mortality.

Pathomechanisms and compensatory efforts related to Parkinsonian speech.

Voice and speech in Parkinson's disease (PD) patients are classically affected by a hypophonia, dysprosody, and dysarthria. The underlying pathomechanisms of these disabling symptoms are not well understood. To identify functional anomalies related to pathophysiology and compensation we compared speech-related brain activity and effective connectivity in early PD patients who did not yet develop voice or speech symptoms and matched controls. During fMRI 20 PD patients ON and OFF levodopa and 20 control participants read 75 sentences covertly, overtly with neutral, or with happy intonation. A cue-target reading paradigm allowed for dissociating task preparation from execution. We found pathologically reduced striato-prefrontal preparatory effective connectivity in early PD patients associated with subcortical (OFF state) or cortical (ON state) compensatory networks. While speaking, PD patients showed signs of diminished monitoring of external auditory feedback. During generation of affective prosody, a reduced functional coupling between the ventral and dorsal striatum was observed. Our results suggest three pathomechanisms affecting speech in PD: While diminished energization on the basis of striato-prefrontal hypo-connectivity together with dysfunctional self-monitoring mechanisms could underlie hypophonia, dysarthria may result from fading speech motor representations given that they are not sufficiently well updated by external auditory feedback. A pathological interplay between the limbic and sensorimotor striatum could interfere with affective modulation of speech routines, which affects emotional prosody generation. However, early PD patients show compensatory mechanisms that could help improve future speech therapies.

Coverage of atypical pathogens for hospitalised patients with community-acquired pneumonia is not guided by clinical parameters.

BACKGROUND: Although most experts recommend empirical antibiotic treatment, covering also atypical bacteria, for patients admitted to an intensive care unit (ICU), the data are not clear for patients admitted to a general ward. European guidelines recommend starting empirical treatment with a beta-lactam antibiotic with or without a macrolide, but the with/without is not clarified. We investigated whether the use of antibiotic coverage for atypical pathogens was guided by clinical parameters. METHODS: We retrospectively analysed 300 patients hospitalised with community-acquired pneumonia. Four parameters for possible atypical pneumonia (age <55 years, abdominal symptoms, sodium <130 mmol/l, immunosuppression) and three for pneumonia severity (pneumonia severity index [PSI], ICU admission, pO2 <8 kPa (60 mm Hg) or O2 saturation <90%) were defined and correlated with the probability of coverage for atypical pathogens. Correlations were calculated using the chi-square test for 2 x 2 tables. RESULTS: Patients younger than 55 years significantly more likely to receive coverage for atypical pathogens than older patients (odds ratio [OR] 2.68; 95% confidence interval [CI] 1.3-5.5, p = 0.009). In patients with a PSI >III the proportion receiving coverage for atypical bacteria was even smaller than in patients with less severe pneumonia (OR 0.77; 95% CI 0.60-0.99, p = 0.03), but no difference was found for PSI >IV compared with PSI ≤IV (OR = 1.03; 95% CI 0.61-1.74, p = 0.9). The other clinical parameters had no effect on antibiotic coverage: ICU admission (OR =1.39; 95% CI 0.87-2.4, p = 0.15); pO2 >8 kPa or O2-Saturation >90% (OR 1.36; 95% CI 0.85-2.17, p = 0.19); abdominal symptoms (OR 1.06; 95% CI 0.51-2.25, p = 0.88); sodium <130 mmol/l (OR 0.63; 95% CI 0.29-1.36, p = 0.2) or immunosuppression (OR 1.007; 95% CI 0.462-44, p = 1). There was also no correlation between the number of clinical parameters present and the coverage of atypical pathogens (r = 0.48). Mortality was no different between patients in whom atypical pathogens were covered compared with those with beta-lactam therapy alone (OR 1.2; 95% CI 0.66-2.25, p = 0.43). CONCLUSION: Physicians have difficulties deciding when to cover atypical pathogens in hospitalised patients with community-acquired pneumonia. Guidelines should clarify under what circumstances combination therapy is warranted.

Tenascin-C downregulates wnt inhibitor dickkopf-1, promoting tumorigenesis in a neuroendocrine tumor model.

The extracellular matrix molecule tenascin-C (TNC) is a major component of the cancer-specific matrix, and high TNC expression is linked to poor prognosis in several cancers. To provide a comprehensive understanding of TNC's functions in cancer, we established an immune-competent transgenic mouse model of pancreatic ß-cell carcinogenesis with varying levels of TNC expression and compared stochastic neuroendocrine tumor formation in abundance or absence of TNC. We show that TNC promotes tumor cell survival, the angiogenic switch, more and leaky vessels, carcinoma progression, and lung micrometastasis. TNC downregulates Dickkopf-1 (DKK1) promoter activity through the blocking of actin stress fiber formation, activates Wnt signaling, and induces Wnt target genes in tumor and endothelial cells. Our results implicate DKK1 downregulation as an important mechanism underlying TNC-enhanced tumor progression through the provision of a proangiogenic tumor microenvironment.

Integrin α6ß1 is the main receptor for vascular laminins and plays a role in platelet adhesion, activation, and arterial thrombosis.

BACKGROUND: Laminins are major components of basement membranes, well located to interact with platelets upon vascular injury. Laminin-111 (α1ß1γ1) is known to support platelet adhesion but is absent from most blood vessels, which contain isoforms with the α2, α4, or α5 chain. Whether vascular laminins support platelet adhesion and activation and the significance of these interactions in hemostasis and thrombosis remain unknown. METHODS AND RESULTS: Using an in vitro flow assay, we show that laminin-411 (α4ß1γ1), laminin-511 (α5ß1γ1), and laminin-521 (α5ß2γ1), but not laminin-211 (α2ß1γ1), allow efficient platelet adhesion and activation across a wide range of arterial wall shear rates. Adhesion was critically dependent on integrin α6ß1 and the glycoprotein Ib-IX complex, which binds to plasmatic von Willebrand factor adsorbed on laminins. Glycoprotein VI did not participate in the adhesive process but mediated platelet activation induced by α5-containing laminins. To address the significance of platelet/laminin interactions in vivo, we developed a platelet-specific knockout of integrin α6. Platelets from these mice failed to adhere to laminin-411, laminin-511, and laminin-521 but responded normally to a series of agonists. α6ß1-Deficient mice presented a marked decrease in arterial thrombosis in 3 models of injury of the carotid, aorta, and mesenteric arterioles. The tail bleeding time and blood loss remained unaltered, indicating normal hemostasis. CONCLUSIONS: This study reveals an unsuspected important contribution of laminins to thrombus formation in vivo and suggests that targeting their main receptor, integrin α6ß1, could represent an alternative antithrombotic strategy with a potentially low bleeding risk.

Attributable risks for childhood overweight: evidence for limited effectiveness of prevention.

OBJECTIVE: Calculation of attributable risks (ARs) of childhood overweight to estimate effectiveness of prevention strategies. METHODS: We used pooled data of 4 population-based German studies including 34240 children and adolescents aged 3 to 18 years to calculate the impact of familial, social, "early life", and lifestyle factors on overweight. ARs (joint for all determinants as well as partial risks) were calculated. RESULTS: The prevalence of childhood overweight was 13.4%. Successfully tackling all determinants can reduce overweight by 77.7% (ie, from 13.4% to 3.0%; = joint AR) with partial effects of treating parental overweight (42.5%); improving social status (14.3%); reducing media time to <1 hour per day (11.4%); and not smoking during pregnancy, low weight gain during pregnancy, and breastfeeding (together 9.5%), respectively. Improving all preventable risk factors (ie, early life factors and lifestyle) the effect is 9.2%. Media time has the strongest effect. CONCLUSIONS: The determinants identified explained 78% of the prevalence of overweight. Taking into account the partial ARs, the effectiveness of lifestyle interventions to prevent overweight in children is limited. Our data argue in favor of interventions aimed at families and social environments, with a major focus on promoting a lower screen time and computer use in children.

Setting up the speech production network: how oscillations contribute to lateralized information routing.

Speech production involves widely distributed brain regions. This MEG study focuses on the spectro-temporal dynamics that contribute to the setup of this network. In 21 participants performing a cue-target reading paradigm, we analyzed local oscillations during preparation for overt and covert reading in the time-frequency domain and localized sources using beamforming. Network dynamics were studied by comparing different dynamic causal models of beta phase coupling in and between hemispheres. While a broadband low frequency effect was found for any task preparation in bilateral prefrontal cortices, preparation for overt speech production was specifically associated with left-lateralized alpha and beta suppression in temporal cortices and beta suppression in motor-related brain regions. Beta phase coupling in the entire speech production network was modulated by anticipation of overt reading. We propose that the processes underlying the setup of the speech production network connect relevant brain regions by means of beta synchronization and prepare the network for left-lateralized information routing by suppression of inhibitory alpha and beta oscillations.

Abnormal Wnt and PI3Kinase signaling in the malformed intestine of lama5 deficient mice.

Laminins are major constituents of basement membranes and are essential for tissue homeostasis. Laminin-511 is highly expressed in the intestine and its absence causes severe malformation of the intestine and embryonic lethality. To understand the mechanistic role of laminin-511 in tissue homeostasis, we used RNA profiling of embryonic intestinal tissue of lama5 knockout mice and identified a lama5 specific gene expression signature. By combining cell culture experiments with mediated knockdown approaches, we provide a mechanistic link between laminin α5 gene deficiency and the physiological phenotype. We show that laminin α5 plays a crucial role in both epithelial and mesenchymal cell behavior by inhibiting Wnt and activating PI3K signaling. We conclude that conflicting signals are elicited in the absence of lama5, which alter cell adhesion, migration as well as epithelial and muscle differentiation. Conversely, adhesion to laminin-511 may serve as a potent regulator of known interconnected PI3K/Akt and Wnt signaling pathways. Thus deregulated adhesion to laminin-511 may be instrumental in diseases such as human pathologies of the gut where laminin-511 is abnormally expressed as it is shown here.

Progenitor cell number is correlated to physical performance in obese children and young adolescents.

UNLABELLED: Juvenile obesity is associated with cardiovascular risk factors. In adults, cardiovascular risk factors and obesity are associated with a decreased number of endothelial progenitor cells. Higher physical fitness correlates with a lower cardiovascular morbidity and increased endothelial progenitor cells. METHODS: CD34 positive, KDR/CD34, CD133/CD34, and CD117/CD34 double positive progenitor cells were measured in 24 obese children and adolescents - 15 female; age: 12.5 plus or minus 2.1 years, body mass index standard deviation score: 2.5 plus or minus 0.5, waist: 88.6 plus or minus 15.0 centimetre, body fat: 24.6 plus or minus 2.2% - participating in the CHILT III programme. Percentage body fat was assessed by skinfold thickness. Peak of oxygen uptake and the respiratory quotient were determined by spiroergometry. RESULTS: No gender differences were found. CD34 positive and CD117 positive/CD34 positive cells correlated with maximum relative watt performance, r is equal to 0.429 and 0.462; p-value less than 0.05. The peak of oxygen uptake correlated with CD34 positive and CD133 positive/CD34 positive cells, r is equal to 0.458 and 0.456; p-value less than 0.05, while no correlations were found between parameters of weight, body composition, and respiratory quotient with progenitor cells. CONCLUSIONS: A higher physical fitness, but not less body fat or body mass index is associated with a higher number of endothelial progenitor cells. These results support the hypothesis that physical fitness and cardiovascular risk in high-risk populations are inversely related. Further research is warranted to clarify the strength of this association and longitudinal effects of a comprehensive obesity programme.

No evidence for an mtDNA role in sperm motility: data from complete sequencing of asthenozoospermic males.

The first complete mitochondrial DNA (mtDNA) sequences (approximately 16,569 bp) in 20 patients with asthenozoospermia and a comparison with 23 new complete mtDNA sequences in teratoasthenozoospermic individuals, confirmed no sharing of specific polymorphisms or specific mitochondrial lineages between these individuals. This is strong evidence against the accepted claim of a major role played by mtDNA in male fertility, once supported by haplogroup association studies based on the screening of hypervariable region I. The hypothesis of maternally driven selection acting in male reproductive success must thus be treated with caution.

The expression pattern of laminin isoforms in Hirschsprung disease reveals a distal peripheral nerve differentiation.

Hirschsprung disease (HD), a developmental disorder, is associated with failure of enteric ganglia formation. Signaling molecules, including secreted basement membrane molecules, derived from the mesenchyme of the gut wall play an important role in the colonization and/or differentiation of the enteric nervous system. The current study aims to define the possible alterations of laminins involved in the pathogenesis of HD. Expression of the various laminin alpha, beta, and gamma chains, was assessed in the aganglionic, transitional, and ganglionic bowel segments of patients with HD or with other motor disorders. Cytoskeletal, neuronal, and glial markers were also included in this study. The major finding highlighted by the present work concerns the clear identification and location of myenteric aganglionic plexuses in HD with some of the laminin antibodies, which reveal a peripheral nerve type of differentiation. Furthermore, we could show an increase of laminin alpha5 chain immunostaining in the dilated muscle of the ganglionic bowel upstream the distal aganglionic region in a subgroup of patients with HD, as well as a relocalization of laminin alpha2 chain in the subepithelial basement membrane. Overall, these basement membrane molecules could provide useful markers for diagnosis of aganglionosis or hypoganglionosis.