Autophagy is a dynamic cellular pathway involved in the turnover of proteins, protein complexes, and organelles through lysosomal degradation. The integrity of postmitotic neurons is heavily dependent on high basal autophagy compared to non-neuronal cells as misfolded proteins and damaged organelles cannot be diluted through cell division. Moreover, neurons contain the specialized structures for intercellular communication, such as axons, dendrites and synapses, which require the reciprocal transport of proteins, organelles and autophagosomes over significant distances from the soma. Defects in autophagy affect the intercellular communication and subsequently, contributing to neurodegeneration. The presence of abnormal autophagic activity is frequently observed in selective neuronal populations afflicted in common neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease and amyotrophic lateral sclerosis. These observations have provoked controversy regarding whether the increase in autophagosomes observed in the degenerating neurons play a protective role or instead contribute to pathogenic neuronal cell death. It is still unknown what factors may determine whether active autophagy is beneficial or pathogenic during neurodegeneration. In this review, we consider both the normal and pathophysiological roles of neuronal autophagy and its potential therapeutic implications for common neurodegenerative diseases.
We aimed to identify and characterize subtypes of Alzheimer’s disease (AD) exhibiting different patterns of regional brain atrophy on MRI using age- and gender-specific norms of regional brain volumes. AD subjects included in the Alzheimer's Disease Neuroimaging Initiative study were classified into subtypes based on standardized values (Z-scores) of hippocampal and regional cortical volumes on MRI with reference to age- and gender-specific norms obtained from 222 cognitively normal (CN) subjects. Baseline and longitudinal changes of clinical characteristics over 2 years were compared across subtypes. Whole-brain-level gray matter (GM) atrophy pattern using voxel-based morphometry (VBM) and cerebrospinal fluid (CSF) biomarkers of the subtypes were also investigated. Of 163 AD subjects, 58.9% were classified as the “both impaired” subtype with the typical hippocampal and cortical atrophy pattern, whereas 41.1% were classified as the subtypes with atypical atrophy patterns: “hippocampal atrophy only” (19.0%), “cortical atrophy only” (11.7%), and “both spared” (10.4%). Voxel-based morphometric analysis demonstrated whole-brain-level differences in overall GM atrophy across the subtypes. These subtypes showed different progression rates over 2 years; and all subtypes had significantly lower CSF amyloid-β1–42 levels compared to CN. In conclusion, we identified four AD subtypes exhibiting heterogeneous atrophy patterns on MRI with different progression rates after controlling the effects of aging and gender on atrophy with normative information. CSF biomarker analysis suggests the presence of Aβ neuropathology irrespective of subtypes. Such heterogeneity of MRI-based neuronal injury biomarker and related heterogeneous progression patterns should be considered in clinical trials and practice with AD patients.
The role of human papilloma virus (HPV) infection in the development of cervical carcinoma is well established, however, the prevalence of HPV DNA in cervical adenocarcinoma varies from study to study. It appears to be caused by a number of factors, one of which is that cervical adenocarcinomas comprise a heterogeneous group of multiple subtypes. To clarify the impact of HPV infection on the development of cervical adenocarcinoma with diverse histological subtypes, we performed a population-based study in Korean women from 15 different institutes for the status of HPV infection in adenocarcinoma of uterine cervix. A total of 432 cervical adenocarcinomas from 1997 to 2001 were reviewed and classified according to the modified WHO classification. For 135 cases, HPV typing was performed with HPV DNA chip (82 cases) and PCR HPV typing (53 cases), using formalin-fixed, paraffin-embedded archival tissue. The overall prevalence of HPV infection in cervical adenocarcinoma was 90%. The infection of HPV 16 and/or HPV 18 accounted for 78% of HPV-positive adenocarcinomas. Multiple HPV types were found in 13% of the cases. The HPV DNA was rarely detected in minimal deviation adenocarcinoma. Interestingly, HPV 16 was a predominant type in endometrioid and villoglandular types, whereas HPV 16 and HPV 18 were detected with equal prevalence in other subtypes. In conclusion, HPV infection, mostly HPV 16 and HPV 18, is highly associated with most of the cervical adenocarcinomas, whereas endometrioid and villoglandular type have a different pattern of HPV infection status. Minimal deviation adenocarcinoma does not seem to be related with HPV infection. Modern Pathology (2005) 18, 528-534, advance online publication, 22 October 2004; doi:10.1038/modpathol.3800316Keywords: cervical adenocarcinoma; HPV infection; HPV DNA Chip; PCR-based HPV typingThe incidence and proportion of adenocarcinoma relative to squamous cell carcinoma in the uterine cervix has been increasing over the past several decades. Recent reports indicated that the adenocarcinoma accounted for 20-25% in uterine cervical cancer compared with only 5-15% in the past. [1][2][3] The epidemiologic risk for cervical adenocarcinoma is similar to those for invasive squamous cell carcinoma, such as multiple sexual partners and the early onset of sexual intercourse, which are related to the risk factors of human papilloma virus (HPV) infection. 4 Whereas the role of HPV infection in the development of cervical squamous cell carcinoma is well established, the pathogenetic role of the HPV in the cervical adenocarcinoma is still
Mer signaling participates in a novel inhibitory pathway in TLR activation. The purpose of the present study was to examine the role of Mer signaling in the down-regulation of TLR4 activation-driven immune responses in mice, i.t.-treated with LPS, using the specific Mer-blocking antibody. At 4 h and 24 h after LPS treatment, expression of Mer protein in alveolar macrophages and lung tissue decreased, sMer in BALF increased significantly, and Mer activation increased. Pretreatment with anti-Mer antibody did not influence the protein levels of Mer and sMer levels. Anti-Mer antibody significantly reduced LPS-induced Mer activation, phosphorylation of Akt and FAK, STAT1 activation, and expression of SOCS1 and -3. Anti-Mer antibody enhanced LPS-induced inflammatory responses, including activation of the NF-κB pathway; the production of TNF-α, IL-1β, and MIP-2 and MMP-9 activity; and accumulation of inflammatory cells and the total protein levels in BALF. These results indicate that Mer plays as an intrinsic feedback inhibitor of the TLR4- and inflammatory mediator-driven immune responses during acute lung injury.
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