Abstract Various attempts have been made to develop artificial conduits for nerve repair, but with limited success. We describe here conduits made from Bombyx mori regenerated silk protein, and ...containing luminal fibres of Spidrex® , a silk-based biomaterial with properties similar to those of spider silk. Assessment in vitro demonstrated that Spidrex® fibres support neurite outgrowth. For evaluation in vivo , silk conduits 10 mm in length and containing 0, 100, 200 or 300 luminal Spidrex® fibres, were implanted to bridge an 8 mm gap in the rat sciatic nerve. At 4 weeks, conduits containing 200 luminal Spidrex® fibres (PN200) supported 62% and 59% as much axon growth as autologous nerve graft controls at mid-conduit and distal nerve respectively. Furthermore, Spidrex® conduits displayed similar Schwann cell support and macrophage response to controls. At 12 weeks, animals implanted with PN200 conduits showed similar numbers of myelinated axons (81%) to controls, similar gastrocnemius muscle innervation, and similar hindpaw stance assessed by Catwalk footprint analysis. Plantar skin innervation was 73% of that of controls. PN200 Spidrex® conduits were also effective at bridging longer (11 and 13 mm) gaps. Our results show that Spidrex® conduits promote excellent axonal regeneration and function recovery, and may have potential for clinical application.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Summary
The thyrotrophin receptor (TSHR) A‐subunit is the autoantigen targeted by pathogenic autoantibodies that cause Graves' hyperthyroidism, a common autoimmune disease in humans. Previously, we ...reported that pathogenic TSHR antibodies develop spontaneously in thyroiditis‐susceptible non‐obese diabetic (NOD).H2h4 mice bearing a human TSHR A‐subunit transgene, which is expressed at low levels in both the thyroid and thymus (Lo‐expressor transgene). The present study tested recent evidence that high intrathymic TSHR expression protects against the development of pathogenic TSHR antibodies in humans. By successive back‐crossing, we transferred to the NOD.H2h4 background a human TSHR A‐subunit transgene expressed at high levels in the thyroid and thymus (Hi‐expressor transgene). In the sixth back‐cross generation (> 98% NOD.H2h4 genome), only transgenic offspring produced spontaneously immunoglobulin (Ig)G class non‐pathogenic human TSHR A‐subunit antibodies. In contrast, both transgenic and non‐transgenic offspring developed antibodies to thyroglobulin and thyroid peroxidase. However, non‐pathogenic human TSHR antibody levels in Hi‐expressor offspring were lower than in Lo‐expressor transgenic mice. Moreover, pathogenic TSHR antibodies, detected by inhibition of TSH binding to the TSHR, only developed in back‐cross offspring bearing the Lo‐expressor, but not the Hi‐expressor, transgene. High versus low expression human TSHR A‐subunit in the NOD.H2h4 thymus was not explained by the transgene locations, namely chromosome 2 (127–147 Mb; Hi‐expressor) and chromosome 1 (22.9–39.3 Mb; low expressor). Nevertheless, using thyroiditis‐prone NOD.H2h4 mice and two transgenic lines, our data support the association from human studies that low intrathymic TSHR expression is associated with susceptibility to developing pathogenic TSHR antibodies, while high intrathymic TSHR expression is protective.
Pathogenic TSHR antibodies, detected by inhibition of TSH binding to the TSHR, only developed in NOD.H2h4 backcross offspring bearing the Lo‐expressor, but not the Hi‐expressor, human TSHR A‐subunit transgene. These findings in a mouse model are consistent with recent evidence in humans that high intra‐thymic TSHR expression protects against the development of pathogenic TSHR antibodies.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
Although sex, genetics, and exposures can individually influence risk for sporadic Parkinson's disease (PD), the joint contributions of these factors to the epigenetic etiology of PD have not been ...comprehensively assessed. Here, we profiled sex-stratified genome-wide blood DNAm patterns, SNP genotype, and pesticide exposure in agricultural workers (71 early-stage PD cases, 147 controls) and explored replication in three independent samples of varying demographics (n = 218, 222, and 872). Using a region-based approach, we found more associations of blood DNAm with PD in females (69 regions) than in males (2 regions, Δβ
| ≥0.03, p
≤ 0.05). For 48 regions in females, models including genotype or genotype and pesticide exposure substantially improved in explaining interindividual variation in DNAm (p
≤ 0.05), and accounting for these variables decreased the estimated effect of PD on DNAm. The results suggested that genotype, and to a lesser degree, genotype-exposure interactions contributed to variation in PD-associated DNAm. Our findings should be further explored in larger study populations and in experimental systems, preferably with precise measures of exposure.
Parkinson disease (PD) is a progressive neurodegenerative disorder that mainly affects the elderly. Recently, the groups of Vilariño-Güell (2011) and Zimprich (2011) simultaneously reported ...identification, using next generation sequencing technologies, of p.Asp620Asn mutations in a novel gene, VPS35, that segregated with autosomal dominant late-onset PD in two large families from Switzerland and Austria, respectively. Screening of the whole gene in additional PD families led to the identification of six more families with the VPS35 p.Asp620Asn mutation (mutation frequencies: 0.0009 and 0.002, respectively). Here we screened the entire VPS35 coding sequence in 246 families with autosomal dominant PD, mostly of French origin. We found the p.Asp620Asn mutation in three French families that was absent in 245 European controls. The mutation frequency, 0.012, is greater than in the previous studies. No other potentially pathogenic VPS35 variants were detected in any of the remaining index cases. The associated phenotype in five patients in the three French families with the VPS35 p.Asp620Asn mutation resembles that of typical, late-onset PD, with a wide range of ages at onset (38 to 67 years).
Abstract Rationale Nicotinic α7 acetylcholine receptors (nAChRs) have been highlighted as a target for cognitive enhancement in schizophrenia. Aim To investigate whether the deficits induced by ...sub-chronic phencyclidine (PCP) in reversal learning and novel object recognition could be attenuated by the selective α7 nAChR full agonist, PNU-282987. Methods Adult female hooded-Lister rats received sub-chronic PCP (2 mg/kg) or vehicle i.p. twice daily for 7 days, followed by 7 days washout. In cohort 1, PCP-treated rats then received PNU-282987 (5, 10, 20 mg/kg; s.c.) or vehicle and were tested in the reversal-learning task. In cohort 2, PCP-treated rats received PNU-282987 (10 mg/kg; s.c.) or saline for 15 days and were tested in the novel object recognition test on day 1 and on day 15, to test for tolerance. Results Sub-chronic PCP produced significant deficits in both cognitive tasks (P < 0.01–0.001). PNU-282987 attenuated the PCP-induced deficits in reversal learning at 10 mg/kg (P < 0.01) and 20 mg/kg (P < 0.001), and in novel object recognition at 10 mg/kg on day 1 (P < 0.01) and on day 15 (P < 0.001). Conclusions These data show that PNU-282987 has efficacy to reverse PCP-induced deficits in two paradigms of relevance to schizophrenia. Results further suggest that 15-day once daily dosing of PNU-282987 (10 mg/kg s.c.) does not cause tolerance in the rat. This study suggests that activation of α7 nAChRs, may represent a suitable strategy for improving cognitive deficits of relevance to schizophrenia.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
We describe the discovery and the structure−activity relationship of a new series of quinoline derivatives acting as selective and highly potent noncompetitive mGlu1 antagonists. We first identified ...cis -10 as a fairly potent mGlu1 antagonist (IC50 = 20 nM) in a cell-based signal transduction assay on the rat mGlu1 receptor expressed in CHO-K1 cells, and then we were able to design and synthesize highly potent compounds on both rat and human mGlu1 receptors as exemplified by compound cis- 64a, which has an antagonist potency of 0.5 nM for the human mGlu1 receptor. We briefly present and discuss the in vitro metabolic stability of the compounds in human liver microsomes. We finally report the pharmacokinetic properties of our lead compound cis -64a.
CD4
and CD8
T cells have a central role in the immune system due to their ability to protect against infection and cancer development without targeting self. Consequently, changes in CD4
and CD8
...T-cell homeostasis can be indicative of an array of serious illnesses, ranging from viral infections to autoimmune diseases. In addition to environmental influences, there is evidence for a genetic component regulating the proportion of CD4
and CD8
T cells in lymphoid organs. Indeed, identifying the genetic determinants defining the frequency of the T-cell subsets is critical as it may reveal a targetable genetic pathway to modulate CD4
and CD8
T-cell numbers, which could be of clinical relevance for multiple disease settings. In this study, we aim to uncover non-MHC genetic factors regulating the proportion of CD4
and CD8
T cells in lymphoid tissues. By investigating linkage analyses on three independent F2 cohorts, namely a rat F2 (BBDP × ACI.1U.LYP) cohort, a mouse 3A9 TCR transgenic F2 (B10.BR × NOD.H2
) cohort and a mouse F2 (C57BL/6 × FVB/N) cohort, we uncover an orthologous non-MHC locus on rat chromosome 1 and mouse chromosome 7 that is linked to T-cell proportion amongst total lymphocytes.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
We report on the expression of ionotropic glutamate receptor subunits in primary neuronal cultures from rat cortex, hippocampus and cerebellum and of metabotropic glutamate (mGlu) receptor subtypes ...in these neuronal cultures as well as in cortical astroglial cultures. We found that the NMDA receptor (NR) subunits NR1, NR2A and NR2B were expressed in all three cultures. Each of the three cultures showed also expression of the four AMPA receptor subunits. Although RT‐PCR detected mRNA of all kainate (KA) subunits in the three cultures, western blot showed only expression of Glu6 and KA2 receptor subunits. The expression analysis of mGlu receptors indicated the presence of all mGlu receptor subtype mRNAs in the three neuronal cultures, except for mGlu2 receptor mRNA, which was not detected in the cortical and cerebellar culture. mGlu1a/α, ‐2/3 and ‐5 receptor proteins were present in all three cultures, whereas mGlu4a and mGlu8a receptor proteins were not detected. Astroglial cultures were grown in either serum‐containing or chemically defined medium. Only mGlu5 receptor protein was found in astroglial cultures grown in serum‐containing medium. When astrocytes were cultured in chemically defined medium, mGlu3, ‐5 and ‐8 receptor mRNAs were detected, but at the protein level, still only mGlu5 receptor was found.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
To establish phenotype-genotype correlations in early-onset Parkinson disease (EOPD), we performed neurologic, neuropsychological, and psychiatric evaluations in a series of patients with and without ...parkin mutations.
Parkin (PARK2) gene mutations are the major cause of autosomal recessive parkinsonism. The usual clinical features are early-onset typical PD with a slow clinical course, an excellent response to low doses of levodopa, frequent treatment-induced dyskinesias, and the absence of dementia.
A total of 44 patients with EOPD (21 with and 23 without parkin mutations) and 9 unaffected single heterozygous carriers of parkin mutations underwent extensive clinical, neuropsychological, and psychiatric examinations.
The neurologic, neuropsychological, and psychiatric features were similar in all patients, except for significantly lower daily doses of dopaminergic treatment and greater delay in the development of levodopa-related fluctuations (p < 0.05) in parkin mutation carriers compared to noncarriers. There was no major difference between the two groups in terms of general cognitive efficiency. Psychiatric manifestations (depression) were more frequent in patients than in healthy single heterozygous parkin carriers but did not differ between the two groups of patients.
Carriers of parkin mutations are clinically indistinguishable from other patients with young-onset Parkinson disease (PD) on an individual basis. Severe generalized loss of dopaminergic neurons in the substantia nigra pars compacta in these patients is associated with an excellent response to low doses of dopa-equivalent and delayed fluctuations, but cognitive impairment and special behavioral or psychiatric symptoms were not more severe than in other patients with early-onset PD.
Autosomal dominant parkinsonism (ADP) is caused in a large percentage of familial and sporadic cases by mutations in the LRRK2 gene, particularly G2019S. It is also caused by mutations in genes ...associated with autosomal dominant cerebellar ataxia (ADCA), notably CAG/CAA repeat expansions in SCA2.
We screened 164 families with ADP for expansions in the SCA2, 3, and 17 genes and for the G2019S mutation in LRRK2. The SCA2 CAG/CAA repeat expansion was sequenced to determine its structure. The phenotypes of patients with ADP caused by the SCA2, LRRK2, and unknown mutations were compared, as well as those of SCA2 patients with interrupted or uninterrupted expansions of the same size.
Three French ADP families had SCA2 mutations. The expansions ranged from 37 to 39 repeats and were interrupted and stable upon transmission. All patients (n = 9) had levodopa-responsive parkinsonism without cerebellar signs. They had significantly more symmetric signs and less rigidity than ADP caused by the G2019S mutation in LRRK2 or by unknown mutations. Interestingly, two sisters carrying both the SCA2 and the G2019S LRRK2 mutations had markedly earlier onset than their mother with only SCA2. In contrast, similar-sized but uninterrupted repeats were associated with ADCA in which cerebellar ataxia was constant and associated only rarely with one or more mild parkinsonian signs.
These results suggest that the configuration of the SCA2 CAG/CAA repeat expansions plays an important role in phenotype variability. Uninterrupted SCA2 repeat expansions found in families with autosomal dominant cerebellar ataxia result in somatic mosaicism and produce large hairpin RNAs, which may interact with double-stranded RNA-binding proteins. These characteristics are modified by interruption of the SCA2 repeat expansion as found in families with autosomal dominant parkinsonism.
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