KIAA1985, a Protein Mutant in Charcot-Marie-Tooth Neuropathy, Links Peripheral Nerve Myelination to Endosomal Recycling Pathways

Charcot-Marie-Tooth neuropathy (CMT) represents a heterogenous group of inherited disorders of the peripheral nervous system. One form of autosomal recessive demyelinating CMT (CMT4C, 5q32) is caused by mutations in the gene encoding KIAA1985, a protein of so far unknown function. Here we show that KIAA1985 is exclusively expressed in Schwann cells. KIAA1985 is tethered to cellular membranes through an N-terminal myristic acid anchor and localizes to the perinuclear recycling compartment. A search for proteins that interact with KIAA1985 identified the small GTPase Rab11, a key regulator of recycling endosome functions. CMT4C-related missense mutations disrupt the KIAA1985/Rab11 interaction. Protein binding studies indicate that KIAA1985 functions as a Rab11 effector, as it interacts only with active forms of Rab11 (WT and Q70L) and does not interact with the GDP locked mutant (S25N). Consistent with a function of Rab11 in Schwann cell myelination, myelin formation was strongly impaired when dorsal root ganglion neurons were co-cultured with Schwann cells infected with Rab11 S25N. Our data indicate that the KIAA1985/Rab11 interaction is relevant for peripheral nerve pathophysiology and place endosomal recycling on the list of cellular mechanisms involved in Schwann cell myelination.

Aging preferentially affects molecular pathways implicated in development and disease of myelinating glial cells

The central and peripheral nervous systems are involved in multiple agedependent neurological deficits that are often attributed to alterations in function of myelinating glial cells. However, the molecular events that underlie the age-related decline of glial cell function are unknown. We used Schwann cells as a model to study biological processes affected in glial cells by aging. We comprehensively profiled gene expression of the Schwann cell-rich mouse sciatic nerve throughout life, from day of birth until senescence (840 days of age). We combined the aging data with the microarray transcriptional data obtained using nerves isolated from Schwann cell-specific neuropathy-inducing mutants MPZCre/þ/Lpin1fE2-3/fE2-3, MPZCre/þ/ScapfE1/fE1 and Pmp22-null mice. A majority of age related transcripts were also affected in the analyzed mouse models of neuropathy (54.4%) and in development (59.5%) indicating a high level of overlapping in implicated molecular pathways. We observed that compared to peripheral nerve development, dynamically changing expression profiles in aging have opposite (anticorrelated) orientation while they copy the orientation of transcriptional changes observed in analyzed neuropathy models. Subsequent clustering and biological annotation of dynamically changing transcripts revealed that the processes most significantly deregulated in aging include inflammatory/ immune response and lipid biosynthesis/metabolism. Importantly, the changes in these pathways were also observed in myelinated oligodendrocyte- rich optic nerves of aged mice, albeit with lower magnitude. This observation suggests that similar biological processes are affected in aging glial cells in central and peripheral nervous systems, however with different dynamics. Our data, which provide the first comprehensive comparison of molecular changes in glial cells in three distinct biological conditions comprising development, aging and disease, provide not only a new inside into the molecular alterations underlying neural system aging but also identify target pathways for potential therapeutical approaches to prevent or delay complications associated with age-related and inherited forms of neuropathies.

Ischemic heart disease and primary care: identifying gender-related differences. An observational study

Background: Gender-related differences are seen in multiple aspects of both health and illness. Ischemic heart disease (IHD) is a pathology in which diagnostic, treatment and prognostic differences are seen between sexes, especially in the acute phase and in the hospital setting. The objective of the present study is to analyze whether there are differences between men and women when examining associated cardiovascular risk factors and secondary pharmacological prevention in the primary care setting. Methods: Retrospective descriptive observational study from January to December of 2006, including 1907 patients diagnosed with ischemic heart disease in the city of Lleida, Spain. The clinical data were obtained from computerized medical records and pharmaceutical records of medications dispensed in pharmacies with official prescriptions. Data was analyzed using bivariate descriptive statistical analysis as well as logistic regression. Results: There were no gender-related differences in screening percentages for arterial hypertension, diabetes, obesity, dyslipemia, and smoking. A greater percentage of women were hypertensive, obese and diabetic compared to men. However, men showed a tendency to achieve control targets more easily than women, with no statistically significant differences. In both sexes cardiovascular risk factors control was inadequate, between 10 and 50%. For secondary pharmaceutical prevention, the percentages of prescriptions were greater in men for anticoagulants, beta-blockers, lipid-lowering agents and angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers, with age group variations up to 10%. When adjusting by age and specific diagnoses, differences were maintained for anticoagulants and lipid-lowering agents. Conclusion: Screening of cardiovascular risk factors was similar in men and women with IHD. Although a greater percentage of women were hypertensive, diabetic or obese, their management of risk factors tended to be worse than men. Overall, a poor control of cardiovascular risk factors was noted. Taken as a whole, more men were prescribed secondary prevention drugs, with differences varying by age group and IHD diagnosis.

Cerebrospinal fluid cortisol and clinical disease progression in MCI and dementia of Alzheimer's type.

Increased peripheral and central nervous system cortisol levels have been reported in Alzheimer's disease (AD) and may reflect dysfunction of cerebral components of the hypothalamic-pituitary-adrenal (HPA) axis. However, brain exposure to high cortisol concentrations may also accelerate disease progression and cognitive decline. The objectives of this study were to investigate whether HPA-axis dysregulation occurs at early clinical stages of AD and whether plasma and CSF cortisol levels are associated with clinical disease progression. Morning plasma and CSF cortisol concentrations were obtained from the subjects with AD dementia, mild cognitive impairment of AD type (MCI-AD), MCI of other type (MCI-O), and controls with normal cognition included in a multicenter study from the German Dementia Competence Network. A clinical and neuropsychological follow-up was performed in a subgroup of participants with MCI-AD, MCI-O, and AD dementia. CSF cortisol concentrations were increased in the subjects with AD dementia or MCI-AD compared with subjects with MCI-O or normal cognition. After controlling for possible confounders including CSF measures of amyloid beta1-42 and total tau, higher baseline CSF cortisol levels were associated with faster clinical worsening and cognitive decline in MCI-AD. The findings suggest that HPA-axis dysregulation occurs at the MCI stage of AD and may accelerate disease progression and cognitive decline.

The year in cardiology 2014: peripheral circulation.

In 2014, the debate on the indication of revascularization in case of asymptomatic carotid disease continued, while another one regarding the use of surgery vs. stenting addressed some new issues regarding the long-term cardiac risk of these patients. Renal arteries interventions trials were disappointing, as neither renal denervation nor renal artery stenting was found associated with better blood pressure management or outcome. In contrast, in lower-extremities artery disease, the endovascular techniques represent in 2014 major alternatives to surgery, even in distal arteries, with new insights regarding the interest of drug-eluting balloons. Regarding the aorta, the ESC published its first guidelines document on the entire vessel, emphasizing on the role of every cardiologist for screening abdominal aorta aneurysm during echocardiography. Among vascular wall biomarkers, the aorta stiffness is of increasing interest with new data and meta-analysis confirming its ability to stratify risk, whereas carotid intima-media thickness showed poor performances in terms of reclassifying patients into risk categories beyond risk scores. Regarding the veins, new data suggest the interest of D-dimers and residual venous thrombosis to help the decision of anti-coagulation prolongation or discontinuation after the initial period of treatment for deep vein thrombosis.

A prospective observational study comparing a non-operator dependent automatic PWV analyser to pulse pressure, in assessing arterial stiffness in hemodialysis.

BACKGROUND: Chronic kidney disease (CKD) accelerates vascular stiffening related to age. Arterial stiffness may be evaluated measuring the carotid-femoral pulse wave velocity (PWV) or more simply, as recommended by KDOQI, monitoring pulse pressure (PP). Both correlate to survival and incidence of cardiovascular disease. PWV can also be estimated on the brachial artery using a Mobil-O-Graph; a non-operator dependent automatic device. The aim was to analyse whether, in a dialysis population, PWV obtained by Mobil-O-Graph (MogPWV) is more sensitive for vascular aging than PP. METHODS: A cohort of 143 patients from 4 dialysis units has been followed measuring MogPWV and PP every 3 to 6 months and compared to a control group with the same risk factors but an eGFR > 30 ml/min. RESULTS: MogPWV contrarily to PP did discriminate the dialysis population from the control group. The mean difference translated in age between the two populations was 8.4 years. The increase in MogPWV, as a function of age, was more rapid in the dialysis group. 13.3% of the dialysis patients but only 3.0% of the control group were outliers for MogPWV. The mortality rate (16 out of 143) was similar in outliers and inliers (7.4 and 8.0%/year). Stratifying patients according to MogPWV, a significant difference in survival was seen. A high parathormone (PTH) and to be dialysed for a hypertensive nephropathy were associated to a higher baseline MogPWV. CONCLUSIONS: Assessing PWV on the brachial artery using a Mobil-O-Graph is a valid and simple alternative, which, in the dialysis population, is more sensitive for vascular aging than PP. As demonstrated in previous studies PWV correlates to mortality. Among specific CKD risk factors only PTH is associated with a higher baseline PWV. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02327962.

Association study of lipoprotein(a) genetic markers, traditional risk factors, and coronary heart disease in HIV-1-infected patients.

Objectives: General population studies have shown associations between copy number variation (CNV) of the LPA gene Kringle-IV type-2 (KIV-2) coding region, single-nucleotide polymorphism (SNP) rs6415084 in LPA and coronary heart disease (CHD). Because risk factors for HIV-infected patients may differ from the general population, we aimed to assess whether these potential associations also occur in HIV-infected patients. Methods: A unicenter, retrospective, case-control (1:3) study. Eighteen HIV-patients with confirmed diagnosis of acute myocardial infarction (AMI) were adjusted for age, gender, and time since HIV diagnosis to 54 HIV-patients without CHD. After gDNA extraction from frozen blood, both CNV and SNP genotyping were performed using real-time quantitative PCR. All genetic and non-genetic variables for AMI were assessed in a logistic regression analysis. Results: Our results did not confirm any association in terms of lipoprotein(a) LPA structural genetic variants when comparing KIV-2 CNV (p = 0.67) and SNP genotypes (p = 0.44) between AMI cases and controls. However, traditional risk factors such as diabetes mellitus, hypertension, and CD4(+) T cell count showed association (p < 0.05) with CHD. Conclusion: Although significant associations of AMI with diabetes, hypertension and CD4(+) T cell count in HIV-patients were found, this study could not confirm the feasibility neither of KIV-2 CNV nor rs6415084 in LPA as genetic markers of CHD in HIV-infected patients.Highlights:● Individuals with HIV infection are at higher risk of coronary heart disease (CHD) than the non-infected population.● Our results showed no evidence of LPA structural genetic variants associated with CHD in HIV-1-infected patients.● Associations were found between diabetes mellitus, arterial hypertension, CD4(+) T cell count, and CHD.● The clinical usefulness of these biomarkers to predict CHD in HIV-1-infected population remains unproven.● Further studies are needed to assess the contribution of common genetic variations to CHD in HIV-infected individuals.

Systemic adalimumab induces peripheral corneal infiltrates: a case report.

BACKGROUND: Tumor necrosis factor-alpha inhibitors are widely used agents in the treatment of immune disorders such as rheumatoid arthritis and inflammatory bowel disease. Despite their anti-inflammatory action, paradoxical drug-induced inflammatory events have been occasionally associated with the use of infliximab, etanercept, and in a lesser extent adalimumab. However, eye involvement is uncommon and anterior uveitis is the only reported ocular adverse manifestation. It can be induced by etanercept, but has also been described during adalimumab therapy. We present here the first report of recurrent peripheral corneal infiltrates following subcutaneous injections of adalimumab. CASE PRESENTATION: A 34 year-old Caucasian woman with Crohn's disease presented to the emergency department with bilateral red eyes and discomfort 36 hours after she received her bimonthly dose of subcutaneous adalimumab. Examination revealed bilateral peripheral corneal infiltrates with characteristic features of immune infiltrates. Symptoms and infiltrates regressed after topical corticosteroid therapy, but recurred after each adalimumab injection over the following weeks. CONCLUSION: Paradoxical immune reactions associated with tumor necrosis factor-alpha inhibitors may result either from hypersensitivity mechanisms, or from immune-complex deposition via anti-adalimumab antibodies. Both mechanisms could explain this newly described manifestation. Care should be taken to search for corneal infiltrates in the event of red eye symptoms during adalimumab therapy since they respond to topical corticosteroids and do not necessarily prompt the discontinuation of the immunosuppressive therapy.

Sustained CTL activation by murine pulmonary epithelial cells promotes the development of COPD-like disease

Chronic obstructive pulmonary disease (COPD) is a lethal progressive lung disease culminating in permanent airway obstruction and alveolar enlargement. Previous studies suggest CTL involvement in COPD progression; however, their precise role remains unknown. Here, we investigated whether the CTL activation receptor NK cell group 2D (NKG2D) contributes to the development of COPD. Using primary murine lung epithelium isolated from mice chronically exposed to cigarette smoke and cultured epithelial cells exposed to cigarette smoke extract in vitro, we demonstrated induced expression of the NKG2D ligand retinoic acid early tran - script 1 (RAET1)as well as NKG2D-mediated cytotoxicity. Furthermore, a genetic model of inducible RAET1 expression on mouse pulmonary epithelial cells yielded a severe emphysematous phenotype characterized by epithelial apoptosis and increased CTL activation, which was reversed by blocking NKG2D activation. We also assessed whether NKG2D ligand expression corresponded with pulmonary disease in human patients by staining airway and peripheral lung tissues from never smokers, smokers with normal lung function, and current and former smokers with COPD. NKG2D ligand expression was independent of NKG2D receptor expression in COPD patients, demonstrating that ligand expression is the limiting factor in CTL activation. These results demonstrate that aberrant, persistent NKG2D ligand expression in the pulmonary epithelium contributes to the development of COPD pathologies.

Inactive Matrix Gla-Protein is associated with arterial stiffness in an adult population-based study

Increased pulse wave velocity (PWV) is a marker of aortic stiffness and an independent predictor of mortality. Matrix Gla-protein (MGP) is a vascular calcification inhibitor that needs vitamin K to be activated. Inactive MGP, known as desphospho-uncarboxylated MGP (dp-ucMGP), can be measured in plasma and has been associated with various cardiovascular markers, cardiovascular outcomes, and mortality. In this study, we hypothesized that high levels of dp-ucMGP are associated with increased PWV. We recruited participants via a multicenter family-based cross-sectional study in Switzerland. Dp-ucMGP was quantified in plasma by sandwich ELISA. Aortic PWV was determined by applanation tonometry using carotid and femoral pulse waveforms. Multiple regression analysis was performed to estimate associations between PWV and dp-ucMGP adjusting for age, renal function, and other cardiovascular risk factors. We included 1001 participants in our analyses (475 men and 526 women). Mean values were 7.87±2.10 m/s for PWV and 0.43±0.20 nmol/L for dp-ucMGP. PWV was positively associated with dp-ucMGP both before and after adjustment for sex, age, body mass index, height, systolic and diastolic blood pressure (BP), heart rate, renal function, low- and high-density lipoprotein, glucose, smoking status, diabetes mellitus, BP and cholesterol lowering drugs, and history of cardiovascular disease (P≤0.01). In conclusion, high levels of dp-ucMGP are independently and positively associated with arterial stiffness after adjustment for common cardiovascular risk factors, renal function, and age. Experimental studies are needed to determine whether vitamin K supplementation slows arterial stiffening by increasing MGP carboxylation.

Chronological order of appearance of extraintestinal manifestations relative to the time of IBD diagnosis in the Swiss Inflammatory Bowel Disease Cohort

BACKGROUND: Data evaluating the chronological order of appearance of extraintestinal manifestations (EIMs) relative to the time of inflammatory bowel disease (IBD) diagnosis is currently lacking. We aimed to assess the type, frequency, and chronological order of appearance of EIMs in patients with IBD. METHODS: Data from the Swiss Inflammatory Bowel Disease Cohort Study were analyzed. RESULTS: The data on 1249 patients were analyzed (49.8% female, median age: 40 [interquartile range, 30-51 yr], 735 [58.8%] with Crohn's disease, 483 [38.7%] with ulcerative colitis, and 31 [2.5%] with indeterminate colitis). A total of 366 patients presented with EIMs (29.3%). Of those, 63.4% presented with 1, 26.5% with 2, 4.9% with 3, 2.5% with 4, and 2.7% with 5 EIMs during their lifetime. Patients presented with the following diseases as first EIMs: peripheral arthritis 70.0%, aphthous stomatitis 21.6%, axial arthropathy/ankylosing spondylitis 16.4%, uveitis 13.7%, erythema nodosum 12.6%, primary sclerosing cholangitis 6.6%, pyoderma gangrenosum 4.9%, and psoriasis 2.7%. In 25.8% of cases, patients presented with their first EIM before IBD was diagnosed (median time 5 mo before IBD diagnosis: range, 0-25 mo), and in 74.2% of cases, the first EIM manifested itself after IBD diagnosis (median: 92 mo; range, 29-183 mo). CONCLUSIONS: In one quarter of patients with IBD, EIMs appeared before the time of IBD diagnosis. Occurrence of EIMs should prompt physicians to look for potential underlying IBD.

Loss of function mutations in HARS cause a spectrum of inherited peripheral neuropathies.

Inherited peripheral neuropathies are a genetically heterogeneous group of disorders characterized by distal muscle weakness and sensory loss. Mutations in genes encoding aminoacyl-tRNA synthetases have been implicated in peripheral neuropathies, suggesting that these tRNA charging enzymes are uniquely important for the peripheral nerve. Recently, a mutation in histidyl-tRNA synthetase (HARS) was identified in a single patient with a late-onset, sensory-predominant peripheral neuropathy; however, the genetic evidence was lacking, making the significance of the finding unclear. Here, we present clinical, genetic, and functional data that implicate HARS mutations in inherited peripheral neuropathies. The associated phenotypic spectrum is broad and encompasses axonal and demyelinating motor and sensory neuropathies, including four young patients presenting with pure motor axonal neuropathy. Genome-wide linkage studies in combination with whole-exome and conventional sequencing revealed four distinct and previously unreported heterozygous HARS mutations segregating with autosomal dominant peripheral neuropathy in four unrelated families (p.Thr132Ile, p.Pro134His, p.Asp175Glu and p.Asp364Tyr). All mutations cause a loss of function in yeast complementation assays, and p.Asp364Tyr is dominantly neurotoxic in a Caenorhabditis elegans model. This study demonstrates the role of HARS mutations in peripheral neuropathy and expands the genetic and clinical spectrum of aminoacyl-tRNA synthetase-related human disease.

Extraintestinal Manifestations of Inflammatory Bowel Disease.

Extraintestinal manifestations (EIM) in inflammatory bowel disease (IBD) are frequent and may occur before or after IBD diagnosis. EIM may impact the quality of life for patients with IBD significantly requiring specific treatment depending on the affected organ(s). They most frequently affect joints, skin, or eyes, but can also less frequently involve other organs such as liver, lungs, or pancreas. Certain EIM, such as peripheral arthritis, oral aphthous ulcers, episcleritis, or erythema nodosum, are frequently associated with active intestinal inflammation and usually improve by treatment of the intestinal activity. Other EIM, such as uveitis or ankylosing spondylitis, usually occur independent of intestinal inflammatory activity. For other not so rare EIM, such as pyoderma gangrenosum and primary sclerosing cholangitis, the association with the activity of the underlying IBD is unclear. Successful therapy of EIM is essential for improving quality of life of patients with IBD. Besides other options, tumor necrosis factor antibody therapy is an important therapy for EIM in patients with IBD.

Fetal programming and epigenetic mechanisms in arterial hypertension.

PURPOSE OF REVIEW: To provide an overview of available evidence of the potential role of epigenetics in the pathogenesis of hypertension and vascular dysfunction. RECENT FINDINGS: Arterial hypertension is a highly heritable condition. Surprisingly, however, genetic variants only explain a tiny fraction of the phenotypic variation and the term 'missing heritability' has been coined to describe this phenomenon. Recent evidence suggests that phenotypic alteration that is unrelated to changes in DNA sequence (thereby escaping detection by classic genetic methodology) offers a potential explanation. Here, we present some basic information on epigenetics and review recent work consistent with the hypothesis of epigenetically induced arterial hypertension. SUMMARY: New technologies that enable the rigorous assessment of epigenetic changes and their phenotypic consequences may provide the basis for explaining the missing heritability of arterial hypertension and offer new possibilities for treatment and/or prevention.

Inflammatory articular disease in patients with inflammatory bowel disease : result of the Swiss IBD Cohort Study

BACKGROUND: Inflammatory bowel diseases (IBD) are systemic conditions that commonly display extraintestinal manifestations. Inflammatory articular disease (IAD: axial or peripheral) is the most common extraintestinal manifestation. The aim of this study was to evaluate the prevalence and the clinical characteristics associated with IAD in patients with IBD. METHODS: We analyzed patients enrolled in the Swiss IBD cohort study. IAD was defined as persistent or recurrent joint pain with an inflammatory pattern (night pain, progressive relief during the day, morning stiffness lasting at least 30 minutes) or the presence of arthritis as diagnosed by the physicians. A multivariate logistic regression was performed to analyze which disease characteristics were independently associated with the presence of IAD. RESULTS: A total of 2353 patients with IBD, 1359 with Crohn's disease, and 994 with ulcerative colitis (UC) were included. Forty-four percent of patients fulfilled the criteria for IAD, whereas 14.5% presented with other extraintestinal manifestations. IAD was associated with Crohn's disease, with female sex, with older age, and generally in patients with more active intestinal disease. Only in UC, IAD was further associated with tobacco smoking and with increasing body mass index. CONCLUSIONS: This population of patients with IBD displays a high prevalence of IAD. IAD was more strongly associated with Crohn's disease than UC. Other risk factors for IAD were female sex, advanced age, active digestive disease, and tobacco consumption in patients with UC, which is interesting given the established association between smoking and other inflammatory arthritides.