Microfracture is an articular cartilage repair technique that works by creating tiny fractures in the underlying bone. However, the predominant repair tissue after microfracture is fibrocartilage. CartiFill™ is cartilage cell scaffold for advanced technique of microfracture. We evaluated the osteochondral healing effect of CartiFill TM and microfracture combination on femoral condyle defect animal model. Twenty NZW rabbits were divided into four groups: 3% CartiFill™ (3% atelocollagen and fibrin glue) implant group, 3% atelocollagen implant group, fibrin glue implant group and non-treatment group. Animals had made femoral condyle defect 4 mm in diameter and 3 mm in depth, and the defect was microfractured using K-wire and immediately implanted accordingly. The animals were sacrificed at 2, 4, 8 and 12 weeks postoperatively, and the specimens were used for macroscopic observation and histological analysis. According to the macroscopic observation, 3% atelocollagen implant and 3% CartiFill™ implant showed smooth, consistent, glistening white tissues. On the contrary, no treatment group and fibrin glue group showed reddish irregular tissues. In histological observation, 3% CartiFill™ group filled the defects sites completely and proceeded to the subchondral bone and cartilage repair by 12 weeks. However, no treatment group didn’t fill the defects sites and didn’t show the subchondral bone repair. Also, all histological scores of 3% CartiFill™ implant (p < 0.05) at 2, 4, 8 and 12 weeks showed significant differences from control group and fibrin glue implant. For regeneration of cartilage on osteochondral lesion, CartiFill™ used in combination with microfracture has provided a structural basis and a good quality cartilage tissue and excellent repair.
Summary Gene-based therapeutic strategies to lower ataxin-2 levels are emerging for neurodegenerative diseases amyotrophic lateral sclerosis (ALS) and spinocerebellar ataxia type 2 (SCA2). To identify additional ways of reducing ataxin-2 levels, we performed a genome-wide screen in human cells for regulators of ataxin-2 and identified RTN4R , the gene encoding the RTN4/NoGo-Receptor, as a top hit. RTN4R knockdown, or treatment with a peptide inhibitor, was sufficient to lower ataxin-2 protein levels in mouse and human neurons in vitro and Rtn4r knockout mice have reduced ataxin-2 levels in vivo . Remarkably, we observed that ataxin-2 shares a role with the RTN4/NoGo-Receptor in limiting axonal regeneration. Reduction of either protein increases axonal regrowth following axotomy. These data define the RTN4/NoGo-Receptor as a novel therapeutic target for ALS and SCA2 and implicate the targeting of ataxin-2 as a potential treatment following nerve injury.
Phosphorylation of proteins on serine or threonine residues preceding proline is a pivotal signaling mechanism regulating cell proliferation. The recent identification and characterization of the enzyme peptidyl–prolyl cis/trans isomerase never in mitosis A (NIMA)-interacting 1 (PIN1) has led to the discovery of a new mechanism regulating phosphorylation in cell signaling. PIN1 specifically binds phosphorylated serine or threonine residues immediately preceding proline (pSer/Thr-Pro) and then regulates protein functions, including catalytic activity, phosphorylation status, protein interactions, subcellular location, and protein stability, by promoting cis/trans isomerization of the peptide bond. Recent results have indicated that such conformational changes following phosphorylation represent a novel signaling mechanism in the regulation of many cellular functions. Understanding this mechanism also provides new insight into the pathogenesis and treatment of human hepatocellular carcinoma. A better understanding of the role of PIN1 in the pathogenesis of hepatocellular carcinoma may lead to the identification of molecular targets for prevention and therapeutic intervention.
Objective To quantitatively determine the density and distribution of activated microglia across cortical regions and hemispheres in the brains of primary progressive aphasia (PPA) participants with pathological diagnoses of frontotemporal lobar degeneration with transactive response DNA‐binding protein‐43 (TDP‐43) inclusions and to examine the relationships between microglial densities, patterns of focal atrophy, (TDP‐43) inclusions, and clinical phenotype. Methods Activated microglia and TDP‐43 inclusions were visualized in whole‐hemisphere brain sections using immunohistochemical methods from five participants with PPA‐TDP. Unbiased stereology was used to bilaterally quantify human leuckocyte antigen/D related–positive activated microglia and TDP‐43 inclusions across five language‐related regions. Density and distribution of both markers were compared across cortical regions and hemispheres, and their relationships to patterns of focal atrophy and clinical phenotype were determined. Results Activated microglia displayed asymmetric distribution favoring the language‐dominant hemisphere, consistent with greater postmortem and/or in vivo atrophy in that hemisphere, in PPA‐TDP. In one participant with no asymmetric atrophy, quantitative distribution of microglia also lacked asymmetry. Patterns of microglial activation also showed variation that favored areas of high atrophy in regions affiliated with language function, demonstrating concordance between patterns of microglial activation, atrophy, and clinical phenotype. TDP‐43 also showed higher inclusion densities in areas of high atrophy than in regions with low atrophy, but no clear relationship with microglia density at a regional level. Interpretation The initial activation of microglia is most likely a response to cortical abnormalities in PPA‐TDP, which contribute to atrophy. The patterns of microglial activation, TDP‐43 inclusion deposition, atrophy, and clinical phenotype suggest that activated microglia may make unique contributions to cortical thinning and TDP‐43 inclusion formation. Ann Neurol 2018;83:1096–1104
Summary Antisense oligonucleotide therapy targeting ATXN2 —a gene in which mutations cause neurodegenerative diseases spinocerebellar ataxia type 2 and amyotrophic lateral sclerosis—has entered clinical trials in humans. Additional methods to lower ataxin-2 levels would be beneficial not only in uncovering potentially cheaper or less invasive therapies, but also in gaining greater mechanistic insight into how ataxin-2 is normally regulated. We performed a genome-wide fluorescence activated cell sorting (FACS)-based CRISPR screen in human cells and identified multiple subunits of the lysosomal vacuolar ATPase (v-ATPase) as regulators of ataxin-2 levels. We demonstrate that Etidronate—a U.S. Food and Drug Administration (FDA)-approved drug that inhibits the v-ATPase—lowers ataxin-2 protein levels in mouse and human neurons. Moreover, oral administration of the drug to mice in their water supply and food is sufficient to lower ataxin-2 levels in the brain. Thus, we uncover Etidronate as a safe and inexpensive compound for lowering ataxin-2 levels and demonstrate the utility of FACS-based screens for identifying targets to modulate levels of human disease proteins.
African swine fever (ASF), a highly contagious and severe hemorrhagic viral disease in swine, is emerging as a major threat not only in Korea but also worldwide. The first confirmed case of ASF in Korea was reported in 2019. Despite the occurrence of ASF in Korea, only a few studies have genetically characterized the causative ASF virus (ASFV). In this study, we aimed to genetically characterize the ASFV responsible for the 2019 outbreak in Korea. The genome of the ASFV isolated during the first outbreak in Korea was analyzed. The Korea/YC1/2019 strain has 188,950 base pairs, with a GC content of 38.4%. The complete genome sequence was compared with other ASFV genomes annotated in the NCBI database. The Korea/YC1/2019 strain shared the highest similarity with Georgia 2007, Belgium 2018/1, and ASFV-wbBS01 strains. This study expands our knowledge of the genetic diversity of ASFV, providing valuable information for epidemiology, diagnostics, therapies, and vaccine development.
While deposition of abnormal proteins and other pathology in cortical gray matter in neurodegenerative disorders has received extensive experimental attention, little is known about the extent and nature of white matter abnormalities. Primary progressive aphasia (PPA) is a clinical dementia syndrome characterized by dissolution of language function and is associated with Alzheimer disease (AD) or frontotemporal lobar degeneration pathology. We have shown extensive activation of microglia in gray matter in PPA brains regardless of the underlying molecular pathology. Here we investigated activation of microglia in cortical white matter in PPA brains with AD or TDP-43 pathology, and its relationship with cortical atrophy. Brains of PPA-AD (n=2) and PPA-TDP (n=2) participants were cut into whole hemisphere sections, and a 1/24 series of sections were processed with immunohistochemical or histopathological procedures to visualize plaques, tangles, TDP-43 inclusions, and HLA-DR-positive activated microglia. Atrophy was quantified using FreeSurfer software in three participants with structural MRI scans collected close to death, and assessed in one participant using clinical MRI scans. Paraffin-embedded sections from additional PPA-TDP participants with GRN mutations were also examined (n=4). Four cases with available MRI displayed pronounced asymmetric atrophy restricted to the perisylvian language network. Whole hemispheric sections displayed substantial asymmetric densities of activated microglia throughout the white matter that surpassed the densities in adjacent gray matter, and allowed demarcation of the white/gray matter junction with the naked eye. Examination of paraffin-embedded sections confirmed presence of high densities of activated microglia in cortical white matter. The highest densities of activated microglia in white matter occurred asymmetrically in cortical areas affiliated with language function, and closely matched patterns of gray matter atrophy detected by MRI scans in each case. Microglia display a pattern of activation in PPA characterized by substantial accumulation in cortical white matter with highest densities at sites of greatest atrophy. While the extent of activation of microglia in white matter in other neurodegenerative disorders is incompletely understood, our findings point to the possibility that activated microglia play an active role in neurodegenerative mechanisms in the white matter, and correspond to in vivo cortical gray matter atrophy.
To quantitatively examine the regional densities and hemispheric distribution of the 43-kDa transactive response DNA-binding protein (TDP-43) inclusions, neurons, and activated microglia in a left-handed patient with right hemisphere language dominance and logopenic-variant primary progressive aphasia (PPA).Phosphorylated TDP-43 inclusions, neurons, and activated microglia were visualized with immunohistochemical and histologic methods. Markers were quantified bilaterally with unbiased stereology in language- and memory-related cortical regions.Clinical MRI indicated cortical atrophy in the right hemisphere, mostly in the temporal lobe. Significantly higher densities of TDP-43 inclusions were present in right language-related temporal regions compared to the left or to other right hemisphere regions. The memory-related entorhinal cortex (ERC) and language regions without significant atrophy showed no asymmetry. Activated microglia displayed extensive asymmetry (R > L). A substantial density of neurons remained in all areas and showed no hemispheric asymmetry. However, perikaryal size was significantly smaller in the right hemisphere across all regions except the ERC. To demonstrate the specificity of this finding, sizes of residual neurons were measured in a right-handed case with PPA and were found to be smaller in the language-dominant left hemisphere.The distribution of TDP-43 inclusions and microglial activation in right temporal language regions showed concordance with anatomic distribution of cortical atrophy and clinical presentation. The results revealed no direct relationship between density of TDP-43 inclusions and activated microglia. Reduced size of the remaining neurons is likely to contribute to cortical atrophy detected by MRI. These findings support the conclusion that there is no obligatory relationship between logopenic PPA and Alzheimer pathology.
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