217 research outputs found
Generation of 3D Skin Equivalents Fully Reconstituted from Human Induced Pluripotent Stem Cells (iPSCs)
Recent generation of patient-specific induced pluripotent stem cells (PS-iPSCs) provides significant advantages for cell- and gene-based therapy. Establishment of iPSC-based therapy for skin diseases requires efficient methodology for differentiating iPSCs into both keratinocytes and fibroblasts, the major cellular components of the skin, as well as the reconstruction of skin structures using these iPSC-derived skin components. We previously reported generation of keratinocytes from human iPSCs for use in the treatment of recessive dystrophic epidermolysis bullosa (RDEB) caused by mutations in the COL7A1 gene. Here, we developed a protocol for differentiating iPSCs into dermal fibroblasts, which also produce type VII collagen and therefore also have the potential to treat RDEB. Moreover, we generated in vitro 3D skin equivalents composed exclusively human iPSC-derived keratinocytes and fibroblasts for disease models and regenerative therapies for skin diseases, first demonstrating that iPSCs can provide the basis for modeling a human organ derived entirely from two different types of iPSC-derived cells
Pharmacologic inhibition of JAK-STAT signaling promotes hair growth
Several forms of hair loss in humans are characterized by the inability of hair follicles to enter the growth phase (anagen) of the hair cycle after being arrested in the resting phase (telogen). Current pharmacologic therapies have been largely unsuccessful in targeting pathways that can be selectively modulated to induce entry into anagen. We show that topical treatment of mouse and human skin with small-molecule inhibitors of the Janus kinase (JAK)–signal transducer and activator of transcription (STAT) pathway results in rapid onset of anagen and subsequent hair growth. We show that JAK inhibition regulates the activation of key hair follicle populations such as the hair germ and improves the inductivity of cultured human dermal papilla cells by controlling a molecular signature enriched in intact, fully inductive dermal papillae. Our findings open new avenues for exploration of JAK-STAT inhibition for promotion of hair growth and highlight the role of this pathway in regulating the activation of hair follicle stem cells
The effect of breed and diet type on the global transcriptome of hepatic tissue in beef cattle divergent for feed efficiency
peer-reviewedBackground
Feed efficiency is an important economic and environmental trait in beef production, which can be measured in terms of residual feed intake (RFI). Cattle selected for low-RFI (feed efficient) have similar production levels but decreased feed intake, while also emitting less methane. RFI is difficult and expensive to measure and is not widely adopted in beef production systems. However, development of DNA-based biomarkers for RFI may facilitate its adoption in genomic-assisted breeding programmes. Cattle have been shown to re-rank in terms of RFI across diets and age, while also RFI varies by breed. Therefore, we used RNA-Seq technology to investigate the hepatic transcriptome of RFI-divergent Charolais (CH) and Holstein-Friesian (HF) steers across three dietary phases to identify genes and biological pathways associated with RFI regardless of diet or breed.
Results
Residual feed intake was measured during a high-concentrate phase, a zero-grazed grass phase and a final high-concentrate phase. In total, 322 and 33 differentially expressed genes (DEGs) were identified across all diets for CH and HF steers, respectively. Three genes, GADD45G, HP and MID1IP1, were differentially expressed in CH when both the high-concentrate zero-grazed grass diet were offered. Two canonical pathways were enriched across all diets for CH steers. These canonical pathways were related to immune function.
Conclusions
The absence of common differentially expressed genes across all dietary phases and breeds in this study supports previous reports of the re-ranking of animals in terms of RFI when offered differing diets over their lifetime. However, we have identified biological processes such as the immune response and lipid metabolism as potentially associated with RFI divergence emphasising the previously reported roles of these biological processes with respect to RFI
Hair Follicle Dermal Cells Support Expansion of Murine and Human Embryonic and Induced Pluripotent Stem Cells and Promote Haematopoiesis in Mouse Cultures
In the hair follicle, the dermal papilla (DP) and dermal sheath (DS) support and maintain proliferation and differentiation of the epithelial stem cells that produce the hair fibre. In view of their regulatory properties, in this study, we investigated the interaction between hair follicle dermal cells (DP and DS) and embryonic stem cells (ESCs); induced pluripotent stem cells (iPSCs); and haematopoietic stem cells. We found that coculture of follicular dermal cells with ESCs or iPSCs supported their prolonged maintenance in an apparently undifferentiated state as established by differentiation assays, immunocytochemistry, and RT-PCR for markers of undifferentiated ESCs. We further showed that cytokines that are involved in ESC support are also expressed by cultured follicle dermal cells, providing a possible explanation for maintenance of ES cell stemness in cocultures. The same cytokines were expressed within follicles in situ in a pattern more consistent with a role in follicle growth activities than stem cell maintenance. Finally, we show that cultured mouse follicle dermal cells provide good stromal support for haematopoiesis in an established coculture model. Human follicular dermal cells represent an accessible and readily propagated source of feeder cells for pluripotent and haematopoietic cells and have potential for use in clinical applications
GWIPS-viz: development of a ribo-seq genome browser
We describe the development of GWIPS-viz (http://gwips.ucc.ie), an online genome browser for viewing ribosome profiling data. Ribosome profiling (ribo-seq) is a recently developed technique that provides genome-wide information on protein synthesis (GWIPS) in vivo. It is based on the deep sequencing of ribosome-protected messenger RNA (mRNA) fragments, which allows the ribosome density along all mRNA transcripts present in the cell to be quantified. Since its inception, ribo-seq has been carried out in a number of eukaryotic and prokaryotic organisms. Owing to the increasing interest in ribo-seq, there is a pertinent demand for a dedicated ribo-seq genome browser. GWIPS-viz is based on The University of California Santa Cruz (UCSC) Genome Browser. Ribo-seq tracks, coupled with mRNA-seq tracks, are currently available for several genomes: human, mouse, zebrafish, nematode, yeast, bacteria (Escherichia coli K12, Bacillus subtilis), human cytomegalovirus and bacteriophage lambda. Our objective is to continue incorporating published ribo-seq data sets so that the wider community can readily view ribosome profiling information from multiple studies without the need to carry out computational processing
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Two-billion-year-old evaporites capture Earth's great oxidation
Funding sources: Simons Foundation (SCOL 339006 to C.L.B.), European Research Council (ERC Horizon 2020 grant 678812 to M.C.), Research Council of Norway (RCN Centres of Excellence funding scheme project 223259 to K.P. and A.L.), Estonian Science Agency (PUT696 to K.K., A.L., K.P., T.K.).Major changes in atmospheric and ocean chemistry occurred in the Paleoproterozoic Era (2.5–1.6 billion years ago). Increasing oxidation dramatically changed Earth’s surface, but few quantitative constraints exist on this important transition. This study describes the sedimentology, mineralogy, and geochemistry of a remarkably preserved two-billion-year-old and ~800 meter-thick evaporite succession from the Onega Basin in Russian Karelia. The deposit consists of a basal unit dominated by halite (~100 m) followed by anhydrite-magnesite (~500 m) and dolomite-magnesite (~200 m) dominated units. The evaporite minerals robustly constraint marine sulfate concentrations to at least 10 millimoles per kilogram of water, representing an oxidant reservoir equivalent to over 20% of the modern ocean-atmosphere oxidizing capacity. These results show that substantial amounts of surface oxidant accumulated during this critical transition in Earth’s oxygenation.PostprintPeer reviewe
Age-appropriate services for people diagnosed with young onset dementia (YOD): a systematic review.
BACKGROUND: Literature agrees that post-diagnostic services for people living with young onset dementia (YOD) need to be age-appropriate, but there is insufficient evidence of 'what works' to inform service design and delivery.
OBJECTIVE: To provide an evidence base of age-appropriate services and to review the perceived effectiveness of current interventions.
METHODS: We undertook a systematic review including all types of research relating to interventions for YOD. We searched PubMed, CINHAL Plus, SCOPUS, EBSCO Host EJS, Social Care Online and Google Scholar, hand-searched journals and carried out lateral searches (July-October 2016). Included papers were synthesised qualitatively. Primary studies were critically appraised. RESULTS: Twenty articles (peer-reviewed [n = 10], descriptive accounts [n = 10]) discussing 195 participants (persons diagnosed with YOD [n = 94], caregivers [n = 91] and other [n = 10]) were identified for inclusion. Services enabled people with YOD to remain living at home for longer. However, service continuity was compromised by short-term project-based commissioning and ad-hoc service delivery.
CONCLUSION: The evidence on the experience of living with YOD is not matched by research and the innovation needed to mitigate the impact of YOD. The inclusion of people with YOD and their caregivers in service design is critical when planning support in order to delay institutional care
The Grizzly, September 30, 2004
USGA has Second Thoughts • Campus Philly Kick-off Week • Lights Out at UC • Where Will You go? UC Study Abroad Programs • Andrew Sullivan to Speak at Ursinus • Easy Access to Social Security Numbers Causes Some Concerns • The Aid Game • Why Study Abroad? • Opinions: Appealing to a Younger Demographic; Experiencing the Miss America Pageant Live; MTV Generation of Choosers and Losers; Ready Maim Fire • Baseball Preview • Women\u27s Soccer Defeats Immaculata • Women\u27s Rugby Claws way to Victoryhttps://digitalcommons.ursinus.edu/grizzlynews/1566/thumbnail.jp
Phase I study of daily and weekly regimens of the orally administered MDM2 antagonist idasanutlin in patients with advanced tumors
SUMMARY: Aim The oral MDM2 antagonist idasanutlin inhibits the p53-MDM2 interaction, enabling p53 activation, tumor growth inhibition, and increased survival in xenograft models. Methods We conducted a Phase I study of idasanutlin (microprecipitate bulk powder formulation) to determine the maximum tolerated dose (MTD), safety, pharmacokinetics, pharmacodynamics, food effect, and clinical activity in patients with advanced malignancies. Schedules investigated were once weekly for 3 weeks (QW × 3), once daily for 3 days (QD × 3), or QD × 5 every 28 days. We also analyzed p53 activation and the anti-proliferative effects of idasanutlin. Results The dose-escalation phase included 85 patients (QW × 3, n = 36; QD × 3, n = 15; QD × 5, n = 34). Daily MTD was 3200 mg (QW × 3), 1000 mg (QD × 3), and 500 mg (QD × 5). Most common adverse events were diarrhea, nausea/vomiting, decreased appetite, and thrombocytopenia. Dose-limiting toxicities were nausea/vomiting and myelosuppression; myelosuppression was more frequent with QD dosing and associated with pharmacokinetic exposure. Idasanutlin exposure was approximately dose proportional at low doses, but less than dose proportional at > 600 mg. Although inter-patient variability in exposure was high with all regimens, cumulative idasanutlin exposure over the whole 28-day cycle was greatest with a QD × 5 regimen. No major food effect on pharmacokinetic exposure occurred. MIC-1 levels were higher with QD dosing, increasing in an exposure-dependent manner. Best response was stable disease in 30.6% of patients, prolonged (> 600 days) in 2 patients with sarcoma. Conclusions Idasanutlin demonstrated dose- and schedule-dependent p53 activation with durable disease stabilization in some patients. Based on these findings, the QD × 5 schedule was selected for further development. TRIAL REGISTRATION: NCT01462175 (ClinicalTrials.gov), October 31, 2011. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10637-021-01141-2
Bridging of Neisseria gonorrhoeae lineages across sexual networks in the HIV pre-exposure prophylaxis era
Whole genome sequencing (WGS) has been used to investigate transmission of Neisseria gonorrhoeae, but to date, most studies have not combined genomic data with detailed information on sexual behaviour to define the extent of transmission across population risk groups (bridging). Here, through combined epidemiological and genomic analysis of 2,186N. gonorrhoeae isolates from Australia, we show widespread transmission of N. gonorrhoeae within and between population groups. We describe distinct transmission clusters associated with men who have sex with men (MSM) and heterosexuals, and men who have sex with men and women (MSMW) are identified as a possible bridging population between these groups. Further, the study identifies transmission of N. gonorrhoeae between HIV-positive and HIV-negative individuals receiving pre-exposure prophylaxis (PrEP). Our data highlight several groups that can be targeted for interventions aimed at improving gonorrhoea control, including returning travellers, sex workers, and PrEP users.D.A.W. (GNT1123854), E.P.F.C. (GNT1091226), and J.C.K. (GNT1142613) are supported by Early Career Fellowships from the National Health and Medical Research
Council (NHMRC) of Australia. B.P.H. is supported by a Practitioner Fellowship from
the NHMRC (GNT1105905). D.J.I. is supported by the European Union’s Horizon 2020
research and innovation programme under grant agreement 643476. Work in this study
was supported by a Project Grant from the NHMRC (GNT1147735) and a Partnership
grant from the NHMRC (GNT1149991). MDU PHL is funded by the Victorian
Department of Health and Human Services
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