1,023 research outputs found
Role of Dendritic Cells in Differential Susceptibility to Viral Demyelinating Disease
Although persistent viral diseases are a global health concern, the mechanisms of differential susceptibility to such infections among individuals are unknown. Here, we report that differential interactions between dendritic cells (DCs) and virus are critical in determining resistance versus susceptibility in the Theiler murine encephalomyelitis virus–induced demyelinating disease model of multiple sclerosis. This virus induces a chronic demyelinating disease in susceptible mice, whereas the virus is completely cleared in resistant strains of mice. DCs from susceptible mice are more permissive to viral infection, resulting in severe deficiencies in development, expansion, and function, in contrast to DCs from resistant mice. Although protective prior to viral infection, higher levels of type I interferons (IFNs) and IFN-γ produced by virus-infected DCs from susceptible mice further contribute to the differential inhibition of DC development and function. An increased DC number and/or acquired resistance of DCs to viral infection render susceptible mice resistant to viral persistence and disease progression. Thus, the differential permissiveness of DCs to infectious agents and its subsequent functional and developmental deficiencies determine the outcome of infection- associated diseases. Therefore, arming DCs against viral infection–induced functional decline may provide a useful intervention for chronic infection-associated diseases
Charge-spin correlation in van der Waals antiferromagenet NiPS3
Strong charge-spin coupling is found in a layered transition-metal
trichalcogenide NiPS3, a van derWaals antiferromagnet, from our study of the
electronic structure using several experimental and theoretical tools:
spectroscopic ellipsometry, x-ray absorption and photoemission spectroscopy,
and density-functional calculations. NiPS3 displays an anomalous shift in the
optical spectral weight at the magnetic ordering temperature, reflecting a
strong coupling between the electronic and magnetic structures. X-ray
absorption, photoemission and optical spectra support a self-doped ground state
in NiPS3. Our work demonstrates that layered transition-metal trichalcogenide
magnets are a useful candidate for the study of correlated-electron physics in
two-dimensional magnetic material.Comment: 6 pages, 3 figur
Mucosal prior to systemic application of recombinant adenovirus boosting is more immunogenic than systemic application twice but confers similar protection against SIV-challenge in DNA vaccine-primed macaques
AbstractWe investigated the immunogenicity and efficacy of a bimodal prime/boost vaccine regimen given by various routes in the Simian immunodeficiency virus (SIV) rhesus monkey model for AIDS. Twelve animals were immunized with SIV DNA-vectors followed by the application of a recombinant adenovirus (rAd5) expressing the same genes either intramuscularly (i.m.) or by oropharyngeal spray. The second rAd5-application was given i.m. All vaccinees plus six controls were challenged orally with SIVmac239 12 weeks post-final immunization.Both immunization strategies induced strong SIV Gag-specific IFN-γ and T-cell proliferation responses and mediated a conservation of CD4+ memory T-cells and a reduction of viral load during peak viremia following infection. Interestingly, the mucosal group was superior to the systemic group regarding breadth and strength of SIV-specific T-cell responses and exhibited lower vector specific immune responses. Therefore, our data warrant the inclusion of mucosal vector application in a vaccination regimen which makes it less invasive and easier to apply
100 fs photo-isomerization with vibrational coherences but low quantum yield in Anabaena Sensory Rhodopsin
Anabaena Sensory Rhodopsin (ASR) stands out among the microbial retinal proteins in that, under light-adaptation (LA) conditions, it binds both the 13-cis isomer and the all-trans isomer of the protonated Schiff base of retinal (PSBR). In the dark-adapted (DA) state, more than 95% of the proteins bear all-trans PSBR, and the protein environment adopts a different equilibrium state. We report the excited state and photo-isomerization kinetics of ASR under different LA conditions. The full data set allows confirming that the photoisomerization of the 13C isomer occurs within 100 fs and indications of an excited and ground state wavepacket launched by the ultrafast non-adiabatic reaction are reported. Even though this recalls the record isomerization time and the coherent reaction scenario of 11-cis PSBR in rhodopsin, the photoisomerization quantum yield (QY) is much lower, actually the lowest value ever reported for retinal proteins (<15%). Noticeably, in ASR the excited state lifetime (ESL) is at least five times larger and the QY is more than twice as large for AT PSBR as compared to 13C PSBR. We argue that ESL and QY cannot be expected to be correlated at all, but that the latter is decided on, as often anticipated, by the wavepacket pathways leading to the conical intersection seam
CK1ε Is Required for Breast Cancers Dependent on β-Catenin Activity
Background: Aberrant -catenin signaling plays a key role in several cancer types, notably colon, liver and breast cancer. However approaches to modulate -catenin activity for therapeutic purposes have proven elusive to date. Methodology: To uncover genetic dependencies in breast cancer cells that harbor active -catenin signaling, we performed RNAi-based loss-of-function screens in breast cancer cell lines in which we had characterized -catenin activity. Here we identify CSNK1E, the gene encoding casein kinase 1 epsilon (CK1) as required specifically for the proliferation of breast cancer cells with activated -catenin and confirm its role as a positive regulator of -catenin-driven transcription. Furthermore, we demonstrate that breast cancer cells that harbor activated -catenin activity exhibit enhanced sensitivity to pharmacological blockade of Wnt/-catenin signaling. We also find that expression of CK1 is able to promote oncogenic transformation of human cells in a -catenin-dependent manner. Conclusions/Significance: These studies identify CK1 as a critical contributor to activated -catenin signaling in cancer and suggest it may provide a potential therapeutic target for cancers that harbor active -catenin. More generally, these observations delineate an approach that can be used to identify druggable synthetic lethal interactions with signaling pathways that are frequently activated in cancer but are difficult to target with the currently available small molecule inhibitors
Clinical Characteristics of a Nationwide Hospital-based Registry of Mild-to-Moderate Alzheimer's Disease Patients in Korea: A CREDOS (Clinical Research Center for Dementia of South Korea) Study
With rapid population aging, the socioeconomic burden caused by dementia care is snowballing. Although a few community-based studies of Alzheimer's disease (AD) have been performed in Korea, there has never been a nationwide hospital-based study thereof. We aimed to identify the demographics and clinical characteristics of mild-to-moderate AD patients from the Clinical Research Center for Dementia of Korea (CREDOS) registry. A total of 1,786 patients were consecutively included from September 2005 to June 2010. Each patient underwent comprehensive neurological examination, interview for caregivers, laboratory investigations, neuropsychological tests, and brain MRI. The mean age was 74.0 yr and the female percentage 67.0%. The mean period of education was 7.1 yr and the frequency of early-onset AD (< 65 yr old) was 18.8%. Among the vascular risk factors, hypertension (48.9%) and diabetes mellitus (22.3%) were the most frequent. The mean score of the Korean version of Mini-Mental State Examination (K-MMSE) was 19.2 and the mean sum of box scores of Clinical Dementia Rating (CDR-SB) 5.1. Based on the well-structured, nationwide, and hospital-based registry, this study provides the unique clinical characteristics of AD and emphasizes the importance of vascular factors in AD in Korea
Primary liposarcoma of the ascending colon: a rare case of mixed type presenting as hemoperitoneum combined with other type of retroperitoneal liposarcoma
<p>Abstract</p> <p>Background</p> <p>Liposarcoma occurs most commonly in the extremities and retroperitoneum, however, it has been rarely observed in the colon.</p> <p>Case Presentation</p> <p>A case is reported a 41-year-old man with liposarcoma of ascending colon which was presented as hemoperitoneum and combined with a different histological type of retroperitoneal liposarcoma. He visited hospital with right lower abdominal pain and palpable mass. Laboratory data including tumor markers were within normal limits, and computed tomography revealed a 15 × 10 cm sized enhancing soft mass. Right hemicolectomy was performed, and after that, a further large retroperitoneal mass was revealed and this was also radically excised. Mixed-type colon liposarcoma and well differentiated type of retroperitoneal liposarcoma were diagnosed in pathologic report. The patient has remained free of disease for 24 months.</p> <p>Conclusions</p> <p>No standardized guidelines have been established for its treatment because too small a number of cases have been reported, but surgical resection was considered the treatment of choice.</p
Synthetic Lethal Interaction between Oncogenic KRAS Dependency and STK33 Suppression in Human Cancer Cells
An alternative to therapeutic targeting of oncogenes is to perform “synthetic lethality” screens for genes that are essential only in the context of specific cancer-causing mutations. We used high-throughput RNA interference (RNAi) to identify synthetic lethal interactions in cancer cells harboring mutant KRAS, the most commonly mutated human oncogene. We find that cells that are dependent on mutant KRAS exhibit sensitivity to suppression of the serine/threonine kinase STK33 irrespective of tissue origin, whereas STK33 is not required by KRAS-independent cells. STK33 promotes cancer cell viability in a kinase activity-dependent manner by regulating the suppression of mitochondrial apoptosis mediated through S6K1-induced inactivation of the death agonist BAD selectively in mutant KRAS-dependent cells. These observations identify STK33 as a target for treatment of mutant KRAS-driven cancers and demonstrate the potential of RNAi screens for discovering functional dependencies created by oncogenic mutations that may enable therapeutic intervention for cancers with “undruggable” genetic alterations.National Institutes of Health (U.S.) (grant R33 CA128625)National Institutes of Health (U.S.) (grant NIH U54 CA112962)National Institutes of Health (U.S.) (grant P01 CA095616)National Institutes of Health (U.S.) (grant P01 CA66996)Starr Cancer ConsortiumDoris Duke Charitable FoundationMPN Research FoundationDeutsche Forschungsgemeinschaft (grant SCHO 1215/1-1)Deutsche Forschungsgemeinschaft (grant FR 2113/1-1)Brain Science FoundationLeukemia & Lymphoma Society of Americ
Protein and lipid MALDI profiles classify breast cancers according to the intrinsic subtype
<p>Abstract</p> <p>Background</p> <p>Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) has been demonstrated to be useful for molecular profiling of common solid tumors. Using recently developed MALDI matrices for lipid profiling, we evaluated whether direct tissue MALDI MS analysis on proteins and lipids may classify human breast cancer samples according to the intrinsic subtype.</p> <p>Methods</p> <p>Thirty-four pairs of frozen, resected breast cancer and adjacent normal tissue samples were analyzed using histology-directed, MALDI MS analysis. Sinapinic acid and 2,5-dihydroxybenzoic acid/α-cyano-4-hydroxycinnamic acid were manually deposited on areas of each tissue section enriched in epithelial cells to identify lipid profiles, and mass spectra were acquired using a MALDI-time of flight instrument.</p> <p>Results</p> <p>Protein and lipid profiles distinguish cancer from adjacent normal tissue samples with the median prediction accuracy of 94.1%. Luminal, HER2+, and triple-negative tumors demonstrated different protein and lipid profiles, as evidenced by permutation <it>P </it>values less than 0.01 for 0.632+ bootstrap cross-validated misclassification rates with all classifiers tested. Discriminatory proteins and lipids were useful for classifying tumors according to the intrinsic subtype with median prediction accuracies of 80.0-81.3% in random test sets.</p> <p>Conclusions</p> <p>Protein and lipid profiles accurately distinguish tumor from adjacent normal tissue and classify breast cancers according to the intrinsic subtype.</p
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PRKACA Mediates Resistance to HER2-Targeted Therapy in Breast Cancer Cells and Restores Anti-Apoptotic Signaling
Targeting HER2 with antibodies or small molecule inhibitors in HER2-positive breast cancer leads to improved survival, but resistance is a common clinical problem. To uncover novel mechanisms of resistance to anti-HER2 therapy in breast cancer, we performed a kinase open reading frame (ORF) screen to identify genes that rescue HER2-amplified breast cancer cells from HER2 inhibition or suppression. In addition to multiple members of the MAPK and PI3K signaling pathways, we discovered that expression of the survival kinases PRKACA and PIM1 rescued cells from anti-HER2 therapy. Furthermore, we observed elevated PRKACA expression in trastuzumab-resistant breast cancer samples, indicating that this pathway is activated in breast cancers that are clinically resistant to trastuzumab-containing therapy. We found that neither PRKACA nor PIM1 restored MAPK or PI3K activation after lapatinib or trastuzumab treatment, but rather inactivated the pro-apoptotic protein BAD, thereby permitting survival signaling through BCL-XL. Pharmacological blockade of BCL-XL/BCL-2 partially abrogated the rescue effects conferred by PRKACA and PIM1, and sensitized cells to lapatinib treatment. These observations suggest that combined targeting of HER2 and the BCL-XL/BCL-2 anti-apoptotic pathway may increase responses to anti-HER2 therapy in breast cancer and decrease the emergence of resistant disease
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