OBJECTIVE-To determine whether maternal intrauterine endotoxin administration leads to neurobehavioral deficits in newborn rabbits. STUDY DESIGN-PregnantNew Zealand white rabbits were injected with 1ml saline (n=8) or 20μg/kg of lipolysaccharide in saline (LPS) (n=8) into the uterine wall on day 28/31 of gestation. On postnatal day 1, kits [saline (n=30) and LPS (n=18) from 4 consecutive litters] underwent neurobehavioral testing. Neonatal brains were stained for microglial cells and myelin.RESULTS-LPS-group kits were hypertonic and demonstrated significant impairment in posture, righting reflex, locomotion and feeding, along with neuroinflammation indicated by activated microglia, and hypomyelination in the periventricular regions. A greater mortality was noted in the LPS group (16 stillbirths from 3 litters vs. 3 from 1 litter).CONCLUSION-Maternal intrauterine endotoxin administration leads to white matter injury and motor deficits in the newborn rabbit resulting in a phenotype that resembles those found in periventricular leukomalacia and cerebral palsy.
Staging laparoscopy can improve treatment decision-making for advanced GC and decrease unnecessary exploratory laparotomy.
Histone deacetylases (HDAC’s) became increasingly important targets for therapy of various diseases, resulting in a pressing need to develop HDAC class- and isoform-selective inhibitors. Class IIa deacetylases possess only minimal deacetylase activity against acetylated histones, but have several other client proteins as substrates through which they participate in epigenetic regulation. Herein, we report the radiosyntheses of the second generation of HDAC class IIa–specific radiotracers: 6-(di-fluoroacetamido)-1-hexanoicanilide (DFAHA) and 6-(tri-fluoroacetamido)-1-hexanoicanilide ([18F]-TFAHA). The selectivity of these radiotracer substrates to HDAC class IIa enzymes was assessed in vitro, in a panel of recombinant HDACs, and in vivo using PET/CT imaging in rats. [18F]TFAHA showed significantly higher selectivity for HDAC class IIa enzymes, as compared to [18F]DFAHA and previously reported [18F]FAHA. PET imaging with [18F]TFAHA can be used to visualize and quantify spatial distribution and magnitude of HDAC class IIa expression-activity in different organs and tissues in vivo. Furthermore, PET imaging with [18F]TFAHA may advance the understanding of HDACs class IIa mediated epigenetic regulation of normal and pathophysiological processes, and facilitate the development of novel HDAC class IIa-specific inhibitors for therapy of different diseases.
Intrauterine inflammation is known to be a risk factor for the development of periventricular leukomalacia (PVL) and cerebral palsy. In recent years, activated microglial cells have been implicated in the pathogenesis of PVL and in the development of white matter injury. Clinical studies have shown the increased presence of activated microglial cells diffusely throughout the white matter in brains of patients with PVL. In vitro studies have reported that activated microglial cells induce oligodendrocyte damage and white matter injury by release of inflammatory cytokines, reactive nitrogen and oxygen species and the production of excitotoxic metabolites. PK11195 [1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinoline carboxamide] is a ligand that is selective for the 18-kDa translocator protein expressed on the outer mitochondrial membrane of activated microglia and macrophages. When labeled with carbon-11, [11C]PK11195 can effectively be used as a ligand in positron emission tomography (PET) studies for the detection of activated microglial cells in various neuroinflammatory and neurodegenerative conditions. In this study, we hypothesized that the magnitude of [11C]-(R)-PK11195 uptake in the newborn rabbit brain, as measured using a small-animal PET scanner, would match the severity of motor deficits resulting from intrauterine inflammation-induced perinatal brain injury. Pregnant New Zealand white rabbits were intrauterinely injected with endotoxin or saline at 28 days of gestation. Kits were born spontaneously at 31 days and underwent neurobehavioral testing and PET imaging following intravenous injection of the tracer [11C]-(R)-PK11195 on the day of birth. The neurobehavioral scores were compared with the change in [11C]PK11195 uptake over the time of scanning, for each of the kits. Upon analysis using receiver operating characteristic curves, an optimal combined sensitivity and specificity for detecting abnormal neurobehavioral scores suggestive of cerebral palsy in the neonatal rabbit was noted for a positive change in [11C]PK11195 uptake in the brain over time on PET imaging (sensitivity of 100% and area under the curve of >0.82 for all parameters tested). The strongest agreements were noted between a positive uptake slope – indicating increased [11C]PK11195 uptake over time – and worsening scores for measures of locomotion (indicated by hindlimb movement, forelimb movement, circular motion and straight- line motion; Cohen’s ĸ >0.75 for each) and feeding (indicated by ability to suck and swallow and turn the head during feeding; Cohen’s ĸ >0.85 for each). This was also associated with increased numbers of activated microglia (mean ratio ± SD of activated to total microglia: 0.96 ± 0.16 in the endotoxin group vs. 0.13 ± 0.08 in controls; p < 0.001) in the internal capsule and corona radiata. Our findings indicate that the magnitude of [11C]PK11195 binding measured in vivo by PET imaging matches the severity of motor deficits ...
Cellular senescence is an important tumor-suppressive mechanism. However, acquisition of a senescence-associated secretory phenotype (SASP) in senescent cells has deleterious effects on the tissue microenvironment and, paradoxically, promotes tumor progression. In a drug screen, we identified melatonin as a novel SASP suppressor in human cells. Strikingly, melatonin blunts global SASP gene expression upon oncogene-induced senescence (OIS). Moreover, poly(ADP-ribose) polymerase-1 (PARP-1), a sensor of DNA damage, was identified as a new melatonin-dependent regulator of SASP gene induction upon OIS. Here, we report two different but potentially coherent epigenetic strategies for melatonin regulation of SASP. The interaction between the telomeric repeat-containing RNA (TERRA) and PARP-1 stimulates the SASP, which was attenuated by 67.9% (illustrated by the case of IL8) by treatment with melatonin. Through binding to macroH2A1.1, PARP-1 recruits CREB-binding protein (CBP) to mediate acetylation of H2BK120, which positively regulates the expression of target SASP genes, and this process is interrupted by melatonin. Consequently, the findings provide novel insight into melatonin's epigenetic role via modulating PARP-1 in suppression of SASP gene expression in OIS-induced senescent cells. Our studies identify melatonin as a novel anti-SASP molecule, define PARP-1 as a new target by which melatonin regulates SASP, and establish a new epigenetic paradigm for a pharmacological mechanism by which melatonin interrupts PARP-1 interaction with the telomeric long noncoding RNA(lncRNA) or chromatin.
Breast cancer patients often suffer from disease relapse and metastasis due to the presence of breast cancer stem-like cells (BCSCs). Numerous studies have reported that high levels of inflammatory factors, including tumor necrosis factor alpha (TNF-α), promote BCSCs. However, the mechanism by which tnf-α promotes BCSCs is unclear. In this study, we demonstrate that TNF-α up-regulates TAZ, a transcriptional co-activator promoting BcSc self-renewal capacity in human breast cancer cell lines. Depletion of TAZ abrogated the increase in BCSCs mediated by TNF-α. TAZ is induced by TNF-α through the non-canonical nf-κB pathway, and our findings suggest that TAZ plays a crucial role in inflammatory factor-promoted breast cancer stemness and could serve as a promising therapeutic target.Breast cancer is one of the most common malignances and a serious threat to women's health worldwide 1 . Inflammation, especially chronic inflammation, plays an important role in cancer initiation and progression 2 . Tumor cells and a variety of leukocytes attracted by tumor cells produce various cytokines and chemokines that affect cancer development 3 . In general, cytokines are divided into two groups. One group comprises pro-inflammatory factors, including tumor necrosis factor alpha (TNF-α), IL1β, IL-6, etc 4,5 . The other group is made of anti-inflammatory factors, including IL-10, IL-13, etc 5 . High levels of pro-inflammatory cytokines promote tumor growth and migration, enhance the survival of malignant cells, suppress adaptive immune responses, and cause resistance to hormones and chemotherapeutic agents 6,7 . Non-steroidal anti-inflammatory drugs decrease the risk for developing and the risk of mortality in breast cancer 3 . Characterization of the mechanisms by which inflammatory cytokines promote breast cancer development may offer new therapeutic opportunities.TNF-α is a well-documented pro-inflammatory cytokine that is up-regulated in breast cancer, and high levels of TNF-α are associated with breast cancer recurrence 8,9 . Additionally, TNF-α levels are positively correlated with tumor grade in serous ovarian tumors 10 . Moreover, TNF-α knockout mice are less susceptible to DMBA-or TPA-induced skin tumors 8 . TNF-α binds to two different receptors, TNF-α receptor 1 and 2 (TNFR1/2), to activate the NF-κB signaling pathway 11,12 . TNFR1/2 activates IKK and subsequently causes IκBα phosphorylation, ubiquitination, and degradation, leading to p65, RelB or p50 translocation to the nucleus. In addition to the canonical NF-κB pathway, TNF-α is able to activate JNK, MAPKs, AKT, and the non-canonical NF-κB pathway [13][14][15] . TNF-α up-regulates over 400 inflammatory genes, including cell-adhesion molecules, anti-apoptotic proteins, inflammatory cytokines, and chemokines 16,17 .Ginalu Storci et al. reported that TNF-α increases the proportion of breast cancer stem-like cells (BCSCs) through NF-κB/HIF1α/Slug 18 . BCSCs are a small subpopulation of the primary breast tumor with differentiation and self-renewal capacities that are re...
Embryonic data and ultrastructural analyses suggest that the primitive endothelium signals undifferentiated mesenchymal cells to migrate to the forming blood vessel and subsequently regulates mural cell growth and behavior. Upon maturation of the blood vessel, chemotactic and mitogenic signals are apparently diminished and differentiated smooth muscle cells normally remain quiescent. This homeostasis is seemingly upset in conditions which lead to pathologies characterized by smooth muscle cell hyperplasia such as atherosclerosis. By culturing endothelial cells at different densities, we attempted to re-create the various stages of vascular development. Whereas media conditioned by sparse endothelial cells stimulate smooth muscle cells, media conditioned by dense endothelial cell cultures are inhibitory. Culture of sparse smooth muscle cells in media conditioned for 3 days by postconfluent endothelial cell cultures leads to dose-dependent and reversible smooth muscle cell inhibition. Furthermore, in the presence of the endothelial cell-derived inhibitor, smooth muscle cells are rendered refractory to mitogens such as fibroblast growth factor and platelet-derived growth factor. The inhibitory activity is not attributable to the well-characterized inhibitors of smooth muscle cell growth, transforming growth factor type-beta, prostaglandin I2, or heparan sulfate proteoglycan. Partial characterization of the inhibitory conditioned media suggests that the active molecule is smaller than 1,000 da, and stable to boiling as well as proteinase K and heparinase digestion. These findings support the concept that there is intercellular communication between endothelial cells and smooth muscle cells and provide evidence for a novel endothelial cell-derived smooth muscle cell growth inhibitor.
About 75% of epithelial ovarian cancer (EOC) patients suffer from relapsing and develop drug resistance after primary chemotherapy. The commonly used clinical examinations and biological tumor tissue models for chemotherapeutic sensitivity are time-consuming and expensive. Research studies showed that the cell morphology-based method is promising to be a new route for chemotherapeutic sensitivity evaluation. Here, we offer how the drug resistance of EOC cells can be assessed through a label-free and high-throughput microfluidic flow cytometer equipped with a digital holographic microscope reinforced by machine learning. It is the first time that such type of assessment is performed to the best of our knowledge. Several morphologic and texture features at a single-cell level have been extracted from the quantitative phase images. In addition, we compared four common machine learning algorithms, including naive Bayes, decision tree, K-nearest neighbors, support vector machine (SVM), and fully connected network. The result shows that the SVM classifier achieves the optimal performance with an accuracy of 92.2% and an area under the curve of 0.96. This study demonstrates that the proposed method achieves high-accuracy, high-throughput, and label-free assessment of the drug resistance of EOC cells. Furthermore, it reflects strong potentialities to develop data-driven individualized chemotherapy treatments in the future.
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