There is no current approved therapy for the ultimately lethal neuro- and cardio-degenerative disease Friedreich's ataxia (FA). Finding minimally-invasive molecular biomarkers of disease progression ...and drug effect could support smaller, shorter clinical trials. Since we and others have noted a deficient oxidative stress response in FA, we investigated the expression of 84 genes involved in oxidative stress, signaling, and protection in control and FA lymphoblasts ranging from 460 to 1122 GAA repeats. Several antioxidant genes responded in a dose-dependent manner to frataxin expression at the mRNA and protein levels, which is inversely correlated with disease progression and severity. We tested the effect of experimental Friedreich's ataxia therapies dimethyl fumarate (DMF) and type 1 histone deacetylase inhibitor (HDACi) on biomarker mRNA expression. We observed that exposure of lymphoblasts to DMF and HDACi dose-dependently unsilenced frataxin expression and restored the potential biomarkers NCF2 and PDLIM1 expression to control levels. We suggest that in addition to frataxin expression, blood lymphoblast levels of NCF2 and PDLIM1 could be useful biomarkers for disease progression and drug effect in future clinical trials of Friedreich's ataxia.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Oxidative stress is thought to be involved in Friedreich's ataxia (FRDA), yet it has not been demonstrated in the target neurons that are first to degenerate. Using the YG8R mouse model of FRDA, ...microarray and neuritic growth experiments were carried out in the dorsal root ganglion (DRG), the primary site of neurodegeneration in this disease.
YG8R hemizygous mice exhibited defects in movement, and DRG neurites had growth defects. Microarray of DRG tissue identified decreased transcripts encoding the antioxidants, including peroxiredoxins, glutaredoxins, and glutathione S-transferase, and these were confirmed by immunoblots and quantitative real-time PCR. Because the decreased gene transcripts are the known targets of the antioxidant transcription factor nuclear factor-E2-related factor-2 (Nrf2), Nrf2 expression was measured; it was significantly decreased at the transcript and protein level in both the DRG and the cerebella of the YG8R hemizygous mouse; further, frataxin expression was significantly correlated with Nrf2 expression. Functionally, in YG8R hemizygous DRG, the total glutathione levels were reduced and explanted cells were more sensitive to the thioredoxin reductase (TxnRD) inhibitor auranofin, a thiol oxidant. In cell models of FRDA, including Schwann and the DRG, frataxin deficiency caused a decreased expression of the Nrf2 protein level in the nucleus, but not a defect in its translocation from the cytosol. Further, frataxin-deficient cells had decreased enzyme activity and expression of TxnRD, which is regulated by Nrf2, and were sensitive the TxnRD inhibitor auranofin.
These results support a mechanistic hypothesis in which frataxin deficiency decreases Nrf2 expression in vivo, causing the sensitivity to oxidative stress in target tissues the DRG and the cerebella, which contributes to the process of neurodegeneration.
Psoriasis is a common inflammatory disorder of the skin and other organs. We have determined that mutations in CARD14, encoding a nuclear factor of kappa light chain enhancer in B cells (NF-kB) ...activator within skin epidermis, account for PSORS2. Here, we describe fifteen additional rare missense variants in CARD14, their distribution in seven psoriasis cohorts (>6,000 cases and >4,000 controls), and their effects on NF-kB activation and the transcriptome of keratinocytes. There were more CARD14 rare variants in cases than in controls (burden test p value = 0.0015). Some variants were only seen in a single case, and these included putative pathogenic mutations (c.424G>A p.Glu142Lys and c.425A>G p.Glu142Gly) and the generalized-pustular-psoriasis mutation, c.413A>C (p.Glu138Ala); these three mutations lie within the coiled-coil domain of CARD14. The c.349G>A (p.Gly117Ser) familial-psoriasis mutation was present at a frequency of 0.0005 in cases of European ancestry. CARD14 variants led to a range of NF-kB activities; in particular, putative pathogenic variants led to levels >2.5× higher than did wild-type CARD14. Two variants (c.511C>A p.His171Asn and c.536G>A p.Arg179His) required stimulation with tumor necrosis factor alpha (TNF-α) to achieve significant increases in NF-kB levels. Transcriptome profiling of wild-type and variant CARD14 transfectants in keratinocytes differentiated probably pathogenic mutations from neutral variants such as polymorphisms. Over 20 CARD14 polymorphisms were also genotyped, and meta-analysis revealed an association between psoriasis and rs11652075 (c.2458C>T p.Arg820Trp; p value = 2.1 × 10−6). In the two largest psoriasis cohorts, evidence for association increased when rs11652075 was conditioned on HLA-Cw∗0602 (PSORS1). These studies contribute to our understanding of the genetic basis of psoriasis and illustrate the challenges faced in identifying pathogenic variants in common disease.
Mitochondria are a source of reactive oxygen species (ROS). Mitochondrial diseases are the result of inherited defects in mitochondrially expressed genes. One potential pathomechanism for ...mitochondrial disease is oxidative stress. Oxidative stress can occur as the result of increased ROS production or decreased ROS protection. The role of oxidative stress in the five most common inherited mitochondrial diseases, Friedreich ataxia, LHON, MELAS, MERRF, and Leigh syndrome (LS), is discussed. Published reports of oxidative stress involvement in the pathomechanisms of these five mitochondrial diseases are reviewed. The strongest evidence for an oxidative stress pathomechanism among the five diseases was for Friedreich ataxia. In addition, a meta-analysis was carried out to provide an unbiased evaluation of the role of oxidative stress in the five diseases, by searching for “oxidative stress” citation count frequency for each disease. Of the five most common mitochondrial diseases, the strongest support for oxidative stress is for Friedreich ataxia (6.42%), followed by LHON (2.45%), MELAS (2.18%), MERRF (1.71%), and LS (1.03%). The increased frequency of oxidative stress citations was significant relative to the mean of the total pool of five diseases (p<0.01) and the mean of the four non-Friedreich diseases (p<0.0001). Thus there is support for oxidative stress in all five most common mitochondrial diseases, but the strongest, significant support is for Friedreich ataxia.
•Mitochondrial diseases are rare, orphan diseases with no known, proven, curative therapy.•The involvement of oxidative stress in the pathomechanisms of five mitochondrial diseases is reviewed.•The strongest support for an oxidative pathomechanism was observed in Friedreich ataxia.•Support for an oxidative pathomechanism was also identified in MELAS, MERRF, LS, and LHON.
Collagen type IV alpha 1 (COL4A1) and alpha 2 (COL4A2) form heterotrimers that constitute a major component of nearly all basement membranes.
and
mutations cause a multisystem disorder that includes ...variable cerebrovascular and skeletal muscle manifestations. The pathogenicity of
and
mutations is generally attributed to impaired secretion into basement membranes. Sodium 4-phenylbutyrate (4PBA) is a US Food and Drug Administration-approved drug that promotes mutant heterotrimer secretion
and
Here, we use different 4PBA treatment paradigms to define therapeutic parameters for preventing cerebrovascular and muscular pathologies in
mutant mice. We show the efficacy of long-term 4PBA treatment in reducing the severity of intracerebral hemorrhages (ICHs) in
mutant mice aged up to 8 months. In addition, we demonstrate that maximal efficacy of 4PBA on ICH and myopathy was achieved when treatment was initiated prenatally, whereby even transient 4PBA administration had lasting benefits after being discontinued. Importantly, postnatal treatment with 4PBA also reduced ICH and skeletal myopathy severities in
mutant mice, which has significant clinical implications for patients with
and
mutations.This article has an associated First Person interview with the first author of the paper.
In this study, the submarine sediments change due to the 2011 off the Pacific coast of Tohoku Earthquake and Tsunami and in subsequent temporal variations of sediments were identified in Ofunato Bay, ...Iwate pref. Sediment distribution and sedimentary environment changes associated with natural and human activities (such as reconstruction works etc.) were considered in combination. The understanding of changes in sedimentary environments caused by natural and human activities is important for infrastructure development for disaster prevention and mitigation in coexistence with the natural environment in coastal areas. The results of this study indicate that the distribution of sediments in Ofunato Bay did not change significantly before and after the earthquake and tsunami. However, some observation sites changed the sediment characteristics shows variety after the tsunami. In the southern part of Sangoshima Island in the central part of the bay, the ratio of gravel sediments increased. Off the bay-mouth breakwater, sandy sediment changed to mud immediately after the tsunami, and muddy sediment changed to sandy sediment again 5 years after the tsunami (October 2016). After October 2016, the characteristics of sediments offshore of the bay-mouth breakwater is similar to that before the earthquake and tsunami. These sediment changes could have been caused by the collapse by the tsunami and subsequent reconstruction of bay-mouth breakwater. Wave ripples were observed on the seafloor after the reconstruction of the breakwater, but not before, suggesting that the effect of the waves on the seafloor has changed by breakwater reconstruction. Construction of structures by humans was considered to have affected sedimentation in coastal sea area and shallow marines.
An important paradigm in evolutionary genetics is that of a delicate balance between genetic variants that favorably boost host control of infection but which may unfavorably increase susceptibility ...to autoimmune disease. Here, we investigated whether patients with psoriasis, a common immune-mediated disease of the skin, are enriched for genetic variants that limit the ability of HIV-1 virus to replicate after infection. We analyzed the HLA class I and class II alleles of 1,727 Caucasian psoriasis cases and 3,581 controls and found that psoriasis patients are significantly more likely than controls to have gene variants that are protective against HIV-1 disease. This includes several HLA class I alleles associated with HIV-1 control; amino acid residues at HLA-B positions 67, 70, and 97 that mediate HIV-1 peptide binding; and the deletion polymorphism rs67384697 associated with high surface expression of HLA-C. We also found that the compound genotype KIR3DS1 plus HLA-B Bw4-80I, which respectively encode a natural killer cell activating receptor and its putative ligand, significantly increased psoriasis susceptibility. This compound genotype has also been associated with delay of progression to AIDS. Together, our results suggest that genetic variants that contribute to anti-viral immunity may predispose to the development of psoriasis.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
We have investigated band structure and edge states of single and AA bilayer honeycomb lattice systems with
p
orbital degeneracy which would be relevant for relatively heavy metals such as ...Pb and Bi. The
p
electrons, which are triply degenerate in the atomic limit, form quadruple degeneracy at K point in a single layer honeycomb lattice. The spin-orbit interaction splits the quartet at K point into two singlets and one doublet which are mixtures of
p
x
,
p
y
and
p
z
orbitals. In the AA bilayer honeycomb lattice, the Dirac node at K point is deformed into circular line node around it. With the intermediate interlayer coupling, there is a degenerate point along Γ-K with
p
z
character. A
p
x
/
p
y
type degenerate point exists under the strong interlayer coupling. This degenerate point is robust against the spin-orbit interaction and the antiferromagnetic spin arrangement only along the intralayer bonds. Without SOI, localized edge states with
p
x
/
p
y
or
p
z
character are created at the zigzag edges both in the single and AA bilayer systems. In the AA bilayer system with SOI, only the
p
x
/
p
y
edge states exhibit the Dirac-like dispersion.
The induction of mitochondrial biogenesis could potentially alleviate mitochondrial and muscle disease. We show here that dimethyl fumarate (DMF) dose-dependently induces mitochondrial biogenesis and ...function dosed to cells in vitro, and also dosed in vivo to mice and humans. The induction of mitochondrial gene expression is more dependent on DMF's target Nrf2 than hydroxycarboxylic acid receptor 2 (HCAR2). Thus, DMF induces mitochondrial biogenesis primarily through its action on Nrf2, and is the first drug demonstrated to increase mitochondrial biogenesis with in vivo human dosing. This is the first demonstration that mitochondrial biogenesis is deficient in Multiple Sclerosis patients, which could have implications for MS pathophysiology and therapy. The observation that DMF stimulates mitochondrial biogenesis, gene expression and function suggests that it could be considered for mitochondrial disease therapy and/or therapy in muscle disease in which mitochondrial function is important.
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