Matters最新文献

{"title":"Mitochondria in hippocampal presynaptic and postsynaptic compartments differ in size as well as intensity.","authors":"David W Freeman,&nbsp;Ronald S Petralia,&nbsp;Ya-Xian Wang,&nbsp;Mark P Mattson,&nbsp;Pamela J Yao","doi":"10.19185/matters.201711000009","DOIUrl":"https://doi.org/10.19185/matters.201711000009","url":null,"abstract":"<p><p>Experimental observations have hinted that, in different compartments of a neuron, mitochondria can be different in their structure, behavior and activity. However, mitochondria have never been systematically compared at the subcellular level in neurons. Using electron microscopy, we analyzed several thousands of mitochondria in the synapses of rat hippocampal neurons <i>in vitro</i> and <i>in vivo</i>. We focused on examining the intensity and size of mitochondria as these structural features have been correlated to the activity of mitochondria. We compared mitochondria in the presynaptic compartment to those in the postsynaptic compartment. We found that, at least in the synapses of hippocampal neurons, presynaptic mitochondria are smaller in diameter and overall higher in intensity (darker) than postsynaptic mitochondria. Our finding highlights the need for developing technologies that would measure the activity of individual mitochondria at single-mitochondria resolution in real time.</p>","PeriodicalId":18333,"journal":{"name":"Matters","volume":"2017 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6492946/pdf/nihms-1017333.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"37216715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Increased whole cerebellar serotonin in aged C57BL/6 mice.","authors":"Nicholas W DeKorver,&nbsp;Dustin Lichty,&nbsp;Marieke van der Hart,&nbsp;Arash Rassoulpour,&nbsp;Stephen J Bonasera","doi":"10.19185/matters.201702000011","DOIUrl":"https://doi.org/10.19185/matters.201702000011","url":null,"abstract":"<p><p>Mobility and locomotor impairments have high prevalence, morbidity, and significant mortality in older adult populations. Cerebellar functional changes have been implicated in the pathogenesis of these age-related mobility and gait deficits unrelated to stroke, Parkinson's disease, or degenerative joint disease. We thus examined total cerebellar glutamate, glutamine, GABA, glycine, dopamine, norepinephrine, tryptophan, serotonin, alanine, threonine, and asparagine content from male 2-3-month (young, <i>n</i> = 6) and 21-24-month-old (aged, <i>n</i> = 6) C₅₇BL/6 mice. Neurotransmitter and amino acid concentrations were determined by high-performance liquid chromatography followed with mass spectroscopy. We found a significant increase in cerebellar serotonin in aged versus young mice, but otherwise no significant phenotypic differences in measured neurotransmitter concentrations. Applying current thought about cerebellar aging and cerebellar serotonergic systems, we consider how this age-related increase in cerebellar serotonin may contribute to gait ataxia.</p>","PeriodicalId":18333,"journal":{"name":"Matters","volume":"2017 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5591457/pdf/nihms893003.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"35502082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"BIN1 localization is distinct from Tau tangles in Alzheimer's disease.","authors":"Pierre De Rossi,&nbsp;Virginie Buggia-Prevot,&nbsp;Robert J Andrew,&nbsp;Sofia V Krause,&nbsp;Elizabeth Woo,&nbsp;Peter T Nelson,&nbsp;Peter Pytel,&nbsp;Gopal Thinakaran","doi":"10.19185/matters.201611000018","DOIUrl":"https://doi.org/10.19185/matters.201611000018","url":null,"abstract":"<p><p><i>BIN1</i> is the second most significant Alzheimer's disease (AD) risk factor gene identified through genome-wide association studies. BIN1 is an adaptor protein that can bind to several proteins including c-Myc, clathrin, adaptor protein-2 and dynamin. <i>BIN1</i> is widely expressed in the brain and peripheral tissue as ubiquitous and tissue-specific alternatively spliced isoforms that regulate membrane dynamics and endocytosis in multiple cell types. The function of BIN1 in the brain and the mechanism(s) by which AD-associated <i>BIN1</i> alleles increase the risk for the disease are not known. BIN1 has been shown to interact with Tau and two studies reported a positive correlation between <i>BIN1</i> expression and neurofibrillary tangle pathology in AD. However, an inverse correlation between BIN1 expression and Tau propagation has also been reported. Moreover, there have been conflicting reports on whether BIN1 is present in tangles. A recent study characterized predominant BIN1 expression in mature oligodendrocytes in the gray matter and the white matter in rodent, and the human brain. Here, we have examined BIN1 localization in the brains of patients with AD using immunohistochemistry and immunofluorescence techniques to analyze BIN1 cellular expression in relation to cellular markers and pathological lesions in AD. We report that BIN1 immunoreactivity in human AD is not associated with neurofibrillary tangles or senile plaques. Moreover, our results show that BIN1 is not expressed by resting and activated microglia, astrocytes, or macrophages in human AD. In accordance with a recent report, low-level <i>de novo</i> BIN1 expression can be observed in a subset of neurons in the AD brain. Further investigations are warranted to understand the complex cellular mechanisms underlying the observed correlation between BIN1 expression and the severity of tangle pathology in AD.</p>","PeriodicalId":18333,"journal":{"name":"Matters","volume":"2017 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5823513/pdf/nihms883418.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"35863006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MYC is not detected in highly proliferating normal spermatogonia but is coupled with CIP2A in testicular cancers.","authors":"Sami Ventelä,&nbsp;Juho-Antti Mäkelä,&nbsp;Rosalie C Sears,&nbsp;Jorma Toppari,&nbsp;Jukka Westermarck","doi":"10.19185/matters.201602000040","DOIUrl":"https://doi.org/10.19185/matters.201602000040","url":null,"abstract":"<p><p>High MYC expression is linked to proliferative activity in most normal tissues and in cancer. MYC also supports self-renewal and proliferation of many types of tissue progenitor cells. Cancerous inhibitor of PP2A (CIP2A) promotes MYC phosphorylation and activity during intestinal crypt regeneration <i>in vivo</i> and in various cancers. CIP2A also supports male germ cell proliferation <i>in vivo</i>. However, the role of MYC in normal germ cell proliferation and spermatogonial progenitor self-renewal is currently unclear. Here, we demonstrate that male germ cells are CIP2A-positive but lack detectable levels of MYC protein; whereas MYC is highly expressed in Leydig cells and peritubular myoid cells contributing thereby to the testicular stem cell niche. On the other hand, MYC was co-expressed with CIP2A in testicular cancers. These results demonstrate that CIP2A and MYC are spatially uncoupled in the regulation of spermatogenesis, but functional relationship between these two human oncoproteins is established during testicular cancer transformation. We propose that further analysis of mechanisms of MYC silencing in spermatogonial progenitors may reveal novel fundamental information relevant to understanding of MYC expression in cancer.</p>","PeriodicalId":18333,"journal":{"name":"Matters","volume":"2016 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2016-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5843371/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"35902315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}