14 research outputs found

    Neuropathology of childhood‐onset basal ganglia degeneration caused by mutation of VAC14

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    ObjectiveTo characterize the clinical features and neuropathology associated with recessive VAC14 mutations.MethodsWhole‐exome sequencing was used to identify the genetic etiology of a rapidly progressive neurological disease presenting in early childhood in two deceased siblings with distinct neuropathological features on post mortem examination.ResultsWe identified compound heterozygous variants in VAC14 in two deceased siblings with early childhood onset of severe, progressive dystonia, and neurodegeneration. Their clinical phenotype is consistent with the VAC14–related childhood‐onset, striatonigral degeneration recently described in two unrelated children. Post mortem examination demonstrated prominent vacuolation associated with degenerating neurons in the caudate nucleus, putamen, and globus pallidus, similar to previously reported ex vivo vacuoles seen in the late‐endosome/lysosome of VAC14‐deficient neurons. We identified upregulation of ubiquitinated granules within the cell cytoplasm and lysosomal‐associated membrane protein (LAMP2) around the vacuole edge to suggest a process of vacuolation of lysosomal structures associated with active autophagocytic‐associated neuronal degeneration.InterpretationOur findings reveal a distinct clinicopathological phenotype associated with recessive VAC14 mutations.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142276/1/acn3487_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142276/2/acn3487.pd

    Resistance to Bleomycin-Induced Lung Fibrosis in MMP-8 Deficient Mice Is Mediated by Interleukin-10

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    BACKGROUND: Matrix metalloproteinases (MMPs) may have pro and antifibrotic roles within the lungs, due to its ability to modulate collagen turnover and immune mediators. MMP-8 is a collagenase that also cleaves a number of cytokines and chemokines. METHODOLOGY AND PRINCIPAL FINDINGS: To evaluate its relevance in lung fibrosis, wildtype and Mmp8(-/-) mice were treated with either intratracheal bleomycin or saline, and lungs were harvested at different time points. Fibrosis, collagen, collagenases, gelatinases, TGFβ and IL-10 were measured in lung tissue. Mmp8(-/-) mice developed less fibrosis than their wildtype counterparts. This was related to an increase in lung inflammatory cells, MMP-9 and IL-10 levels in these mutant animals. In vitro experiments showed that MMP-8 cleaves murine and human IL-10, and tissue from knockout animals showed decreased IL-10 processing. Additionally, lung fibroblasts from these mice were cultured in the presence of bleomycin and collagen, IL-10 and STAT3 activation (downstream signal in response to IL-10) measured by western blotting. In cell cultures, bleomycin increased collagen synthesis only in wildtype mice. Fibroblasts from knockout mice did not show increased collagen synthesis, but increased levels of unprocessed IL-10 and STAT3 phosphorylation. Blockade of IL-10 reverted this phenotype, increasing collagen in cultures. CONCLUSIONS: According to these results, we conclude that the absence of MMP-8 has an antifibrotic effect by increasing IL-10 and propose that this metalloprotease could be a relevant modulator of IL-10 metabolism in vivo

    Cerebral hypomyelination associated with biallelic variants of FIG4

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    The lipid phosphatase gene FIG4 is responsible for Yunisâ Varón syndrome and Charcotâ Marieâ Tooth disease Type 4J, a peripheral neuropathy. We now describe four families with FIG4 variants and prominent abnormalities of central nervous system (CNS) white matter (leukoencephalopathy), with onset in early childhood, ranging from severe hypomyelination to mild undermyelination, in addition to peripheral neuropathy. Affected individuals inherited biallelic FIG4 variants from heterozygous parents. Cultured fibroblasts exhibit enlarged vacuoles characteristic of FIG4 dysfunction. Two unrelated families segregate the same Gâ >â A variant in the +1 position of intron 21 in the homozygous state in one family and compound heterozygous in the other. This mutation in the splice donor site of exon 21 results in readâ through from exon 20 into intron 20 and truncation of the final 115 Câ terminal amino acids of FIG4, with retention of partial function. The observed CNS white matter disorder in these families is consistent with the myelination defects in the FIG4 null mouse and the known role of FIG4 in oligodendrocyte maturation. The families described here the expanded clinical spectrum of FIG4 deficiency to include leukoencephalopathy.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149294/1/humu23720-sup-0001-Supp_Mat_Lenk_2018.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149294/2/humu23720.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149294/3/humu23720_am.pd

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

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    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

    Collagenase-2 Deficiency or Inhibition Impairs Experimental Autoimmune Encephalomyelitis in Mice

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    Matrix metalloproteinases (MMPs) have been implicated in a variety of human diseases, including neuroimmunological disorders such as multiple sclerosis. However, the recent finding that some MMPs play paradoxical protective roles in these diseases has made necessary the detailed study of the specific function of each family member in their pathogenesis. To determine the relevance of collagenase-2 (MMP-8) in experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis, we have performed two different analyses involving genetic and biochemical approaches. First, we have analyzed the development of EAE in mutant mouse deficient in MMP-8, with the finding that the absence of this proteolytic enzyme is associated with a marked reduction in the clinical symptoms of EAE. We have also found that MMP-8(-/-) mice exhibit a marked reduction in central nervous system-infiltrating cells and demyelinating lesions. As a second approach, we have carried out a pharmacological inhibition of MMP-8 with a selective inhibitor against this protease (IC(50) = 0.4 nM). These studies have revealed that the administration of the MMP-8 selective inhibitor to mice with EAE also reduces the severity of the disease. Based on these findings, we conclude that MMP-8 plays an important role in EAE development and propose that this enzyme may be a novel therapeutic target in human neuro-inflammatory diseases such as multiple sclerosis

    Schematic representation of the mechanisms by which absence of MMP-8 ameliorates lung fibrosis.

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    <p>In normal mice (left), presence of MMP-8 facilitates the resolution of inflammation, thus decreasing MMP-9 (by the clearance of neutrophils) and IL-10 (by cleavage). The increased TGFβ promotes fibrosis. In absence of MMP-8 (right), there are increased levels of MMP-9 and IL-10, both of them with antifibrotic properties. IL-10 can also inhibit TGFβ synthesis. For further details, see text.</p

    MMP activity in each experimental group.

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    <p><b>A</b>: MMP-8 increased after bleomycin instillation. As expected, no MMP-8 was detected in knockout mice (n≥7 per group). <b>B–C</b>: Collagenolytic activity of lung tissue homogenates from wildtype and knockout mice 3 days (B) and 3 weeks (C) after bleomycin instillation (n = 3 per group). There are no significant differences between genotypes. <b>D</b>: MMP-9 has an acute increase after bleomycin instillation only in knockout mice (n≥7 per group). <b>E</b>: MMP-2 increases in both wildtype and knockout mice 3 weeks after injury (n≥7 per group). <b>F</b>: Representative western blotting and gelatin zymography used to quantify these MMPs. G–H: Immunohistochemical staining of MMP-8 (G) and MMP-9 (H) after bleomycin instillation. <sup>1,2,3</sup>p<0.05 in post-hoc test when compared against 3 days (1), 3 weeks (2), 6 weeks (3) within the same genotype and treatment; *p<0.05 when compared against wildtype within the same time and treatment; <sup>#</sup>p<0.05 when compared against saline within the same time and genotype.</p

    Increased inflammatory infiltrate activity in <i>Mmp8<sup>−/−</sup></i> mice treated with bleomycin.

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    <p><b>A</b>: Myeloperoxidase was considered a surrogate marker of neutrophilic infiltration of lung tissue (n≥7 per group). <b>B</b>: The number of myeloperoxidase-positive cells was higher in knockout mice. <b>C–D</b>: Representative immunohistochemistry for myeloperoxidase in wildtype (C) and knockout (D) animals. <sup>1,2,3</sup>P<0.05 in post-hoc test when compared against 3 days (1), 3 weeks (2), 6 weeks (3) within the same genotype and treatment; *p<0.05 when compared against wildtype within the same time and treatment; <sup>#</sup>p<0.05 when compared against saline within the same time and genotype.</p

    <i>In vitro</i> cleavage of IL-10.

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    <p>MMP-8 processing of murine (<b>A</b>) and human (<b>B</b>) IL-10 in vitro. Cleavage results in a 14 kDa fragment in addition to intact IL-10 (18 kDa). In vivo cleavage (<b>C</b>) also occurs. Although there is a 14 kDa fragment in both genotypes, indicating overlapping of other proteases, the percentage of intact IL-10 is significantly higher (*p<0.05) in knockout mice (<b>D</b>), demonstrating the relevance of MMP-8 in IL-10 metabolism in vivo.</p
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