190 research outputs found
Polyisoprenylated benzophenone, garcinol, a natural histone acetyltransferase inhibitor, represses chromatin transcription and alters global gene expression
Histone acetylation is a diagnostic feature of transcriptionally active genes. The proper recruitment and function of histone acetyltransferases (HATs) and deacetylases (HDACs) are key regulatory steps for gene expression and cell cycle. Functional defects of either of these enzymes may lead to several diseases, including cancer. HATs and HDACs thus are potential therapeutic targets. Here we report that garcinol, a polyisoprenylated benzophenone derivative from Garcinia indica fruit rind, is a potent inhibitor of histone acetyltransferases p300 (IC50≈7 μM) and PCAF (IC50≈5 μM) both in vitro and in vivo. The kinetic analysis shows that it is a mixed type of inhibitor with an increased affinity for PCAF compared with p300. HAT activity-dependent chromatin transcription was strongly inhibited by garcinol, whereas transcription from DNA template was not affected. Furthermore, it was found to be a potent inducer of apoptosis, and it alters (predominantly down-regulates) the global gene expression in HeLa cells
A modular focal plane detector system for the heavy ion reaction analyzer at NSC, New Delhi
A detector system has been developed for the focal plane of the HIRA. It consists of two independent detectors, a low-pressure multiwire proportional counter (LP-MWPC) followed by a split-anode ionization detector. Details of the design and test results are presented. Using slow preamplifiers, the position resolution is ≥1 mm and the time resolution is estimated to be 1.5 ns for the LP-MWPC. The ionization detector gives 2.4% energy resolution for 150 MeV 28Si scattered off a gold target and the ΔZ/Z obtained for 28Si+27Al is 1/42 for Z=14. Some results for fusion and transfer studies for the 48Ti+58Ni and 28Si+68Zn systems, respectively, at energies around the Coulomb barrier, are presented to highlight the performance of the detector system
Neural development features: Spatio-temporal development of the Caenorhabditis elegans neuronal network
The nematode Caenorhabditis elegans, with information on neural connectivity,
three-dimensional position and cell linage provides a unique system for
understanding the development of neural networks. Although C. elegans has been
widely studied in the past, we present the first statistical study from a
developmental perspective, with findings that raise interesting suggestions on
the establishment of long-distance connections and network hubs. Here, we
analyze the neuro-development for temporal and spatial features, using birth
times of neurons and their three-dimensional positions. Comparisons of growth
in C. elegans with random spatial network growth highlight two findings
relevant to neural network development. First, most neurons which are linked by
long-distance connections are born around the same time and early on,
suggesting the possibility of early contact or interaction between connected
neurons during development. Second, early-born neurons are more highly
connected (tendency to form hubs) than later born neurons. This indicates that
the longer time frame available to them might underlie high connectivity. Both
outcomes are not observed for random connection formation. The study finds that
around one-third of electrically coupled long-range connections are late
forming, raising the question of what mechanisms are involved in ensuring their
accuracy, particularly in light of the extremely invariant connectivity
observed in C. elegans. In conclusion, the sequence of neural network
development highlights the possibility of early contact or interaction in
securing long-distance and high-degree connectivity
B4 suppresses lymphoma progression by inhibiting fibroblast growth factor binding protein 1 through intrinsic apoptosis
Lymphoma positions as the fifth most common cancer, in the world, reporting remarkable deaths every year. Several promising strategies to counter this disease recently include utilizing small molecules that specifically target the lymphoma cellular proteins to overwhelm its progression. FGFBP1 is a soluble intracellular protein that progresses cancer cell proliferation and is upregulated in several cancers. Therefore, inhibiting FGFBP1 could significantly slow down lymphoma progression through triggering apoptosis. Thus, in this study, a flavonoid B4, isolated from Cajanus cajan, has been investigated for its effects of B4 on lymphoma, specifically as an FGFBP1 inhibitor. B4 could selectively hinder the growth of lymphoma cells by inducing caspase-dependent intrinsic apoptosis through G1/S transition phase cell cycle arrest. RNA sequencing analysis revealed that B4 regulates the genes involved in B-cell proliferation and DNA replication by inhibiting FGFBP1 in vitro. B4 increases the survival rate of lymphoma mice. B4 also represses the growth of patient-derived primary lymphoma cells through FGFBP1 inhibition. Drug affinity responsive target stability experimentations authorize that B4 powerfully binds to FGFBP1. The overexpression of FGFBP1 raises the pharmacological sensitivity of B4, supplementing its specific action on lymphoma cells. This study pioneers the estimation of B4 as a possible anticancer agent for lymphoma treatment. These outcomes highlight its selective inhibitory effects on lymphoma cell growth by downregulating FGFBP1 expression through intrinsic apoptosis, causing mitochondrial and DNA damage, ultimately leading to the inhibition of lymphoma progression. These suggest B4 may be a novel FGFBP1 inhibitor for the lymphoma treatment
The natural history of primary sclerosing cholangitis in 781 children. A multicenter, international collaboration
There are limited data on the natural history of primary sclerosing cholangitis (PSC) in children. We aimed to describe the disease characteristics and long-term outcomes of pediatric PSC. We retrospectively collected all pediatric PSC cases from 36 participating institutions and conducted a survival analysis from the date of PSC diagnosis to dates of diagnosis of portal hypertensive or biliary complications, cholangiocarcinoma, liver transplantation, or death. We analyzed patients grouped by disease phenotype and laboratory studies at diagnosis to identify objective predictors of long-term outcome. We identified 781 patients, median age 12 years, with 4,277 person-years of follow-up; 33% with autoimmune hepatitis, 76% with inflammatory bowel disease, and 13% with small duct PSC. Portal hypertensive and biliary complications developed in 38% and 25%, respectively, after 10 years of disease. Once these complications developed, median survival with native liver was 2.8 and 3.5 years, respectively. Cholangiocarcinoma occurred in 1%. Overall event-free survival was 70% at 5 years and 53% at 10 years. Patient groups with the most elevated total bilirubin, gamma-glutamyltransferase, and aspartate aminotransferase-to-platelet ratio index at diagnosis had the worst outcomes. In multivariate analysis PSC-inflammatory bowel disease and small duct phenotypes were associated with favorable prognosis (hazard ratios 0.6, 95% confidence interval 0.5-0.9, and 0.7, 95% confidence interval 0.5-0.96, respectively). Age, gender, and autoimmune hepatitis overlap did not impact long-term outcome.
CONCLUSION:
PSC has a chronic, progressive course in children, and nearly half of patients develop an adverse liver outcome after 10 years of disease; elevations in bilirubin, gamma-glutamyltransferase, and aspartate aminotransferase-to-platelet ratio index at diagnosis can identify patients at highest risk; small duct PSC and PSC-inflammatory bowel disease are more favorable disease phenotypes
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