186 research outputs found
EP<sub>2</sub> receptor antagonism reduces peripheral and central hyperalgesia in a preclinical mouse model of endometriosis
Endometriosis is an incurable gynecological disorder characterized by debilitating pain and the establishment of innervated endometriosis lesions outside the uterus. In a preclinical mouse model of endometriosis we demonstrated overexpression of the PGE2-signaling pathway (including COX-2, EP2, EP4) in endometriosis lesions, dorsal root ganglia (DRG), spinal cord, thalamus and forebrain. TRPV1, a PGE2-regulated channel in nociceptive neurons was also increased in the DRG. These findings support the concept that an amplification process occurs along the pain neuroaxis in endometriosis. We then tested TRPV1, EP2, and EP4 receptor antagonists: The EP2 antagonist was the most efficient analgesic, reducing primary hyperalgesia by 80% and secondary hyperalgesia by 40%. In this study we demonstrate reversible peripheral and central hyperalgesia in mice with induced endometriosis
The Therapeutic Implications of Plasticity of the Cancer Stem Cell Phenotype
The cancer stem cell hypothesis suggests that tumors contain a small population of cancer cells that have the ability to undergo symmetric self-renewing cell division. In tumors that follow this model, cancer stem cells produce various kinds of specified precursors that divide a limited number of times before terminally differentiating or undergoing apoptosis. As cells within the tumor mature, they become progressively more restricted in the cell types to which they can give rise. However, in some tumor types, the presence of certain extra- or intracellular signals can induce committed cancer progenitors to revert to a multipotential cancer stem cell state. In this paper, we design a novel mathematical model to investigate the dynamics of tumor progression in such situations, and study the implications of a reversible cancer stem cell phenotype for therapeutic interventions. We find that higher levels of dedifferentiation substantially reduce the effectiveness of therapy directed at cancer stem cells by leading to higher rates of resistance. We conclude that plasticity of the cancer stem cell phenotype is an important determinant of the prognosis of tumors. This model represents the first mathematical investigation of this tumor trait and contributes to a quantitative understanding of cancer
Integrating livelihoods and conservation in protected areas: Understanding the role and stakeholder views on prospects for non-timber forest products, a Bangladesh case study
Protected areas (PAs) represent a key global strategy in biodiversity conservation. In tropical developing countries, the management of PAs is a great challenge as many contain resources on which local communities rely. Collection and trading of non-timber forest products (NTFPs) is a well-established forest-based livelihood strategy, which has been promoted as a potential means for enhanced conservation and improved rural livelihoods in recent years, even though the sustainability or ecological implications have rarely been tested. We conducted an exploratory survey to understand the role and stakeholder views on conservation prospects and perceived ecological feasibility of NTFPs and harvesting schemes in a northeastern PA of Bangladesh, namely the Satchari National Park. Households (n = 101) were interviewed from three different forest dependency categories, adopting a stratified random sampling approach and using a semi-structured questionnaire. The study identified 13 locally important NTFPs, with five being critically important to supporting local livelihoods. Our study suggests that collection, processing and trading in NTFPs constitutes the primary occupation for about 18% of local inhabitants and account for an estimated 19% of their cash annual income. The household consensus on issues relating to NTFPs and their prospective role in conservation was surprisingly high, with 48% of respondents believing that promotion of NTFPs in the PA could have positive conservation value. The majority (71%) of households also had some understanding of the ecological implications of NTFP harvesting, sustainability (53%) and possible management and monitoring regimes (100%). With little known about their real application in the field, our study suggests further investigations are required to understand the ecological compatibility of traditional NTFP harvesting patterns and management. ยฉ 2010 Taylor & Francis
The Human Proteins MBD5 and MBD6 Associate with Heterochromatin but They Do Not Bind Methylated DNA
BACKGROUND: MBD5 and MBD6 are two uncharacterized mammalian proteins that contain a putative Methyl-Binding Domain (MBD). In the proteins MBD1, MBD2, MBD4, and MeCP2, this domain allows the specific recognition of DNA containing methylated cytosine; as a consequence, the proteins serve as interpreters of DNA methylation, an essential epigenetic mark. It is unknown whether MBD5 or MBD6 also bind methylated DNA; this question has interest for basic research, but also practical consequences for human health, as MBD5 deletions are the likely cause of certain cases of mental retardation. PRINCIPAL FINDINGS: Here we report the first functional characterization of MBD5 and MBD6. We have observed that the proteins colocalize with heterochromatin in cultured cells, and that this localization requires the integrity of their MBD. However, heterochromatic localization is maintained in cells with severely decreased levels of DNA methylation. In vitro, neither MBD5 nor MBD6 binds any of the methylated sequences DNA that were tested. CONCLUSIONS: Our data suggest that MBD5 and MBD6 are unlikely to be methyl-binding proteins, yet they may contribute to the formation or function of heterochromatin. One isoform of MBD5 is highly expressed in oocytes, which suggests a possible role in epigenetic reprogramming after fertilization
Regulation of Inflammatory Gene Expression in PBMCs by Immunostimulatory Botanicals
Many hundreds of botanicals are used in complementary and alternative medicine for therapeutic use as antimicrobials and immune stimulators. While there exists many centuries of anecdotal evidence and few clinical studies on the activity and efficacy of these botanicals, limited scientific evidence exists on the ability of these botanicals to modulate the immune and inflammatory responses. Using botanogenomics (or herbogenomics), this study provides novel insight into inflammatory genes which are induced in peripheral blood mononuclear cells following treatment with immunomodulatory botanical extracts. These results may suggest putative genes involved in the physiological responses thought to occur following administration of these botanical extracts. Using extracts from immunostimulatory herbs (Astragalus membranaceus, Sambucus cerulea, Andrographis paniculata) and an immunosuppressive herb (Urtica dioica), the data presented supports previous cytokine studies on these herbs as well as identifying additional genes which may be involved in immune cell activation and migration and various inflammatory responses, including wound healing, angiogenesis, and blood pressure modulation. Additionally, we report the presence of lipopolysaccharide in medicinally prepared extracts of these herbs which is theorized to be a natural and active component of the immunostimulatory herbal extracts. The data presented provides a more extensive picture on how these herbs may be mediating their biological effects on the immune and inflammatory responses
Proteoglycan-4 Regulates Fibroblast to Myofibroblast Transition and Expression of Fibrotic Genes in the Synovium
Background: Synovial tissue fibrosis is common in advanced OA with features including the presence of stress fiber-positive myofibroblasts and deposition of cross-linked collagen type-I. Proteoglycan-4 (PRG4) is a mucinous glycoprotein secreted by synovial fibroblasts and is a major component of synovial fluid. PRG4 is a ligand of the CD44 receptor. Our objective was to examine the role of PRG4-CD44 interaction in regulating synovial tissue fibrosis in vitro and in vivo.
Methods: OA synoviocytes were treated with TGF-ฮฒ ยฑ PRG4 for 24h and ฮฑ-SMA content was determined using immunofluorescence. Rhodamine-labeled rhPRG4 was incubated with OA synoviocytes ยฑ anti-CD44 or isotype control antibodies and cellular uptake of rhPRG4 was determined following a 30-min incubation and ฮฑ-SMA expression following a 24-h incubation. HEK-TGF-ฮฒ cells were treated with TGF-ฮฒ ยฑ rhPRG4 and Smad3 phosphorylation was determined using immunofluorescence and TGF-ฮฒ/Smad pathway activation was determined colorimetrically. We probed for stress fibers and focal adhesions (FAs) in TGF-ฮฒ-treated murine fibroblasts and fibroblast migration was quantified ยฑ rhPRG4. Synovial expression of fibrotic markers: ฮฑ-SMA, collagen type-I, and PLOD2 in Prg4 gene-trap (Prg4GT) and recombined Prg4GTR animals were studied at 2 and 9 months of age. Synovial expression of ฮฑ-SMA and PLOD2 was determined in 2-month-old Prg4GT/GT&Cd44โ/โ and Prg4GTR/GTR&Cd44โ/โ animals.
Results: PRG4 reduced ฮฑ-SMA content in OA synoviocytes (p \u3c 0.001). rhPRG4 was internalized by OA synoviocytes via CD44 and CD44 neutralization attenuated rhPRG4โs antifibrotic effect (p \u3c 0.05). rhPRG4 reduced pSmad3 signal in HEKTGF- ฮฒ cells (p \u3c 0.001) and TGF-ฮฒ/Smad pathway activation (p \u3c 0.001). rhPRG4 reduced the number of stress fiberpositive myofibroblasts, FAs mean size, and cell migration in TGF-ฮฒ-treated NIH3T3 fibroblasts (p \u3c 0.05). rhPRG4 inhibited fibroblast migration in a macrophage and fibroblast co-culture model without altering active or total TGF-ฮฒ levels. Synovial tissues of 9-month-old Prg4GT/GT animals had higher ฮฑ-SMA, collagen type-I, and PLOD2 (p \u3c 0.001) content and Prg4 re-expression reduced these markers (p \u3c 0.01). Prg4 re-expression also reduced ฮฑ-SMA and PLOD2 staining in CD44-deficient mice.
Conclusion: PRG4 is an endogenous antifibrotic modulator in the joint and its effect on myofibroblast formation is partially mediated by CD44, but CD44 is not required to demonstrate an antifibrotic effect in vivo
Inflammatory Gene Regulatory Networks in Amnion Cells Following Cytokine Stimulation: Translational Systems Approach to Modeling Human Parturition
A majority of the studies examining the molecular regulation of human labor have
been conducted using single gene approaches. While the technology to produce
multi-dimensional datasets is readily available, the means for facile analysis
of such data are limited. The objective of this study was to develop a systems
approach to infer regulatory mechanisms governing global gene expression in
cytokine-challenged cells in vitro, and to apply these methods
to predict gene regulatory networks (GRNs) in intrauterine tissues during term
parturition. To this end, microarray analysis was applied to human amnion
mesenchymal cells (AMCs) stimulated with interleukin-1ฮฒ, and differentially
expressed transcripts were subjected to hierarchical clustering, temporal
expression profiling, and motif enrichment analysis, from which a GRN was
constructed. These methods were then applied to fetal membrane specimens
collected in the absence or presence of spontaneous term labor. Analysis of
cytokine-responsive genes in AMCs revealed a sterile immune response signature,
with promoters enriched in response elements for several inflammation-associated
transcription factors. In comparison to the fetal membrane dataset, there were
34 genes commonly upregulated, many of which were part of an acute inflammation
gene expression signature. Binding motifs for nuclear factor-ฮบB were
prominent in the gene interaction and regulatory networks for both datasets;
however, we found little evidence to support the utilization of
pathogen-associated molecular pattern (PAMP) signaling. The tissue specimens
were also enriched for transcripts governed by hypoxia-inducible factor. The
approach presented here provides an uncomplicated means to infer global
relationships among gene clusters involved in cellular responses to
labor-associated signals
Evaluating the Effects of SARS-CoV-2 Spike Mutation D614G on Transmissibility and Pathogenicity.
Global dispersal and increasing frequency of the SARS-CoV-2 spike protein variant D614G are suggestive of a selective advantage but may also be due to a random founder effect. We investigate the hypothesis for positive selection of spike D614G in the United Kingdom using more than 25,000 whole genome SARS-CoV-2 sequences. Despite the availability of a large dataset, well represented by both spike 614 variants, not all approaches showed a conclusive signal of positive selection. Population genetic analysis indicates that 614G increases in frequency relative to 614D in a manner consistent with a selective advantage. We do not find any indication that patients infected with the spike 614G variant have higher COVID-19 mortality or clinical severity, but 614G is associated with higher viral load and younger age of patients. Significant differences in growth and size of 614G phylogenetic clusters indicate a need for continued study of this variant
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Background: Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. // Methods: We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung's disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. // Findings: We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung's disease) from 264 hospitals (89 in high-income countries, 166 in middle-income countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58ยท0%) were male. Median gestational age at birth was 38 weeks (IQR 36โ39) and median bodyweight at presentation was 2ยท8 kg (2ยท3โ3ยท3). Mortality among all patients was 37 (39ยท8%) of 93 in low-income countries, 583 (20ยท4%) of 2860 in middle-income countries, and 50 (5ยท6%) of 896 in high-income countries (p<0ยท0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90ยท0%] of ten in low-income countries, 97 [31ยท9%] of 304 in middle-income countries, and two [1ยท4%] of 139 in high-income countries; pโค0ยท0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2ยท78 [95% CI 1ยท88โ4ยท11], p<0ยท0001; middle-income vs high-income countries, 2ยท11 [1ยท59โ2ยท79], p<0ยท0001), sepsis at presentation (1ยท20 [1ยท04โ1ยท40], p=0ยท016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4โ5 vs ASA 1โ2, 1ยท82 [1ยท40โ2ยท35], p<0ยท0001; ASA 3 vs ASA 1โ2, 1ยท58, [1ยท30โ1ยท92], p<0ยท0001]), surgical safety checklist not used (1ยท39 [1ยท02โ1ยท90], p=0ยท035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1ยท96, [1ยท41โ2ยท71], p=0ยท0001; parenteral nutrition 1ยท35, [1ยท05โ1ยท74], p=0ยท018). Administration of parenteral nutrition (0ยท61, [0ยท47โ0ยท79], p=0ยท0002) and use of a peripherally inserted central catheter (0ยท65 [0ยท50โ0ยท86], p=0ยท0024) or percutaneous central line (0ยท69 [0ยท48โ1ยท00], p=0ยท049) were associated with lower mortality. // Interpretation: Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between low-income, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030
- โฆ