60 research outputs found
Supplemental Material, FigureS1_Hardikar - Epigenetic and Transcriptome Profiling Identifies a Population of Visceral Adipose-Derived Progenitor Cells with the Potential to Differentiate into an Endocrine Pancreatic Lineage
No full textSupplemental Material, FigureS1_Hardikar for Epigenetic and Transcriptome Profiling Identifies a Population of Visceral Adipose-Derived Progenitor Cells with the Potential to Differentiate into an Endocrine Pancreatic Lineage by Michael D. Williams, Mugdha V. Joglekar, Sarang N. Satoor, Wilson Wong, Effie Keramidaris, Amanda Rixon, Philip O’Connell, Wayne J. Hawthorne, Geraldine M. Mitchell, and Anandwardhan A. Hardikar in Cell Transplantation</p
Supplemental Material, FigureS2_Hardikar - Epigenetic and Transcriptome Profiling Identifies a Population of Visceral Adipose-Derived Progenitor Cells with the Potential to Differentiate into an Endocrine Pancreatic Lineage
No full textSupplemental Material, FigureS2_Hardikar for Epigenetic and Transcriptome Profiling Identifies a Population of Visceral Adipose-Derived Progenitor Cells with the Potential to Differentiate into an Endocrine Pancreatic Lineage by Michael D. Williams, Mugdha V. Joglekar, Sarang N. Satoor, Wilson Wong, Effie Keramidaris, Amanda Rixon, Philip O’Connell, Wayne J. Hawthorne, Geraldine M. Mitchell, and Anandwardhan A. Hardikar in Cell Transplantation</p
Supplemental Material, Figure_S3 - Epigenetic and Transcriptome Profiling Identifies a Population of Visceral Adipose-Derived Progenitor Cells with the Potential to Differentiate into an Endocrine Pancreatic Lineage
Full text linkSupplemental Material, Figure_S3 for Epigenetic and Transcriptome Profiling Identifies a Population of Visceral Adipose-Derived Progenitor Cells with the Potential to Differentiate into an Endocrine Pancreatic Lineage by Michael D. Williams, Mugdha V. Joglekar, Sarang N. Satoor, Wilson Wong, Effie Keramidaris, Amanda Rixon, Philip O’Connell, Wayne J. Hawthorne, Geraldine M. Mitchell, and Anandwardhan A. Hardikar in Cell Transplantation</p
Droplet digital PCR for measuring absolute copies of gene transcripts in human islet-derived progenitor cells
No full textTranscript analysis is a routinely used method to assess the expression profile of progenitor cells at different stages starting from their isolation to differentiation into specific lineages. It is a powerful way to understand similarities and differences between different cell types as well to estimate successful differentiation process. Transcript measurement is most commonly done using polymerase chain reaction (PCR) but other methods such as in situ hybridization, RNA sequencing are available. The quantitative PCR using TaqMan chemistry is a highly sensitive and reproducible method that measures gene transcripts as a relative abundance. With recent advances in technology, absolute quantitation of genes to single copy level is possible using digital PCR platforms. Digital PCR is an improved method of PCR in which a single reaction is partitioned into multiple mini reactions. Gene transcripts are measured in each of these mini reactions thereby improving assay sensitivity and making absolute quantitation possible. Here we describe the generation of human islet-derived progenitor cells and measuring gene transcripts in these cells at different passages using digital droplet PCR
Supplementary_Table_1_new - Epigenetic and Transcriptome Profiling Identifies a Population of Visceral Adipose-Derived Progenitor Cells with the Potential to Differentiate into an Endocrine Pancreatic Lineage
No full textSupplementary_Table_1_new for Epigenetic and Transcriptome Profiling Identifies a Population of Visceral Adipose-Derived Progenitor Cells with the Potential to Differentiate into an Endocrine Pancreatic Lineage by Michael D. Williams, Mugdha V. Joglekar, Sarang N. Satoor, Wilson Wong, Effie Keramidaris, Amanda Rixon, Philip O’Connell, Wayne J. Hawthorne, Geraldine M. Mitchell, and Anandwardhan A. Hardikar in Cell Transplantation</p
Striving for balance in the lung ecosystem: unravelling the ECM and its crosstalk with immune cells in COPD
Full text linkChronic obstructive pulmonary disease (COPD) is a lung disease that affects the airways and alveoli. Central to its pathology are chronic inflammation and abnormalities in the extracellular matrix (ECM) within the lungs. The dynamic interplay between immune cells and ECM often generates ECM fragments, increasingly recognised as potential biomarkers of disease endotypes and monitoring progression. However, the impact of aberrant ECM on immune cell responses in COPD remains underexplored. In this thesis, we aimed to further characterise lung ECM in COPD and investigate its crosstalk with immune cells. We utilised native human lung tissues or innovative in vitro models derived from them. Our study highlighted differential composition of lung ECM as a distinct feature of severe COPD. We also noted a higher degree of crosslinking and altered proportions of organised to disorganised collagens in COPD lung tissue. Further, the applicability of protein fragments as markers of COPD were also investigated, where calprotectin (a major cytosolic component of neutrophils) emerged as a promising biomarker for milder COPD, warranting further exploration of its role in disease pathology. Our study using decellularised lung ECM hydrogels showed that COPD microenvironment activates human lung fibroblasts leading to contraction and increased stiffness of the microenvironment. The addition of monocytes, however, mitigates this response suggesting a protective role. Overall, this thesis underlined the importance of characterising the ECM in disease and its role in regulating cellular responses. Several novel research avenues for understanding disease mechanisms and identifying clinically relevant COPD biomarkers were also identified
Human fetal pancreatic insulin-producing cells proliferate in vitro
No full textThere have been considerable efforts towards understanding the potential of human pancreatic endocrine cells to proliferate and transition into mesenchymal cell populations. Since rodent studies have demonstrated that mouse insulinproducing cells do not proliferate in vitro, a similar possibility has been considered for human islet endocrine cells. Considering the inherent differences in mouse and human pancreatic islets, we decided to assess the potential of human fetal pancreatic insulin-producing cells to proliferate in vitro. We studied the proliferative potential of human fetal pancreatic islet-derived populations from second or third trimester fetal pancreas and characterized the cells that grow out during their expansion. We have used seven different approaches including in situ hybridization and immunostaining, quantitative estimation of multiple gene transcripts in populations as well as in single cells, clonal analysis of islet cells, assessment of heritable marks of active insulin promoter, and thymidine analog-based lineage tracing. Our studies demonstrate that human fetal pancreatic insulin-producing cells proliferate in vitro to generate mesenchymal cell populations. Interestingly, epigenetic modifications that mark open chromatin conformation of insulin promoter regions are retained even after a million fold expansion/proliferation in vitro. These findings demonstrate that hormone-producing cells in pancreatic islets proliferate in vitro and retain epigenetic marks that characterize an active insulin promoter. Such in vitro-derived mesenchymal cells may be of potential use in cellreplacement therapy for diabetes
Circulating microRNAs in diabetes progression : discovery, validation, and research translation
No full textDiabetes, in all of its forms, is a disease state that demonstrates wide ranging pathological effects throughout the body. Until now, the only method of diagnosing and monitoring the progression of diabetes was through the measurement of blood glucose. Unfortunately, beta cell dysfunction initiates well before the clinical onset of diabetes, and so the development of an effective biomarker signature is of paramount importance to predict and monitor the progression of this disease. MicroRNAs (miRNAs/miRs) are small (18–22 nucleotide) noncoding (nc)RNAs that post-transcriptionally regulate endogenous gene expression by targeted inhibition or degradation of messenger (m)RNA. Recently, miRNAs have shown great promise as biomarkers as some exhibit differential expression in multiple disease states, including type 1 and type 2 diabetes (T1D/T2D). Furthermore, miRNAs are quite stable in circulation, resistant to freeze-thaw and pH-mediated degradation, and are relatively easy to detect using quantitative (q)PCR. Here, we discuss microRNAs that may form a diabetes biomarker signature. To identify these transcripts we outline miRNAs that play a central role in pancreas development and diabetes, as well as previously identified miRNAs with differential expression in individuals with T1D and T2D. Validation and refinement of a miRNA biomarker signature for diabetes would allow identification and intervention of individuals at risk of this disease, as well as stratification and monitoring of patients with established diabetes
Expression of islet-specific microRNAs during human pancreatic development
No full textDuring pancreatic islet development, sequential changes in gene expression are known to be necessary for efficient differentiation and function of the endocrine pancreas. Several studies till now have demonstrated that microRNAs (miRNAs), which regulate translation of gene transcripts, influence gene expression cascades involved in pancreas development. Some of these miRNAs; miR-7 and miR-375 have been known to be expressed at high levels in pancreas and are also known to be involved in Zebrafish pancreas development as well as insulin secretion in mice. We demonstrate here that 4 different islet-specific microRNAs (miR-7, miR-9, miR-375 and miR-376) are expressed at high levels during human pancreatic islet development. Of these, miR-375, is seen to be differentially expressed in human islet β- as well as non-β-cells. Though no significant difference in abundance of miR-375 was noted in either cell type, analysis of islet-specific miRNA and mRNA in single cells show that non-β cells contain higher levels of miR-375. Our data demonstrate that miRNAs that are known to be regulated during Zebrafish pancreatic development may play similar role in human pancreatic islet development
Crosslink bio-adhesives for bronchoscopic lung volume reduction:current status and future direction
Full text linkSeveral bronchoscopic lung volume reduction (BLVR) treatments have been developed to reduce hyperinflation in emphysema patients. Lung bio-adhesives are among the most promising new BLVR treatment options, as they potentially provide a permanent solution for emphysematous patients after only a single application. To date, bio-adhesives have mainly been used as haemostats and tissue sealants, while their application in permanently contracting and sealing hyperinflated lung tissue has recently been identified as a novel and enticing opportunity. However, a major drawback of the current adhesive technology is the induction of severe inflammatory responses and adverse events upon administration. In our review, we distinguish between and discuss various natural, semi-synthetic and synthetic tissue haemostats and sealants that have been used for pulmonary applications such as sealing air/fluid leaks. Furthermore, we present an overview of the different materials including AeriSeal and autologous blood that have been used to achieve lung volume reduction and discuss their respective advantages and drawbacks. In conclusion, we describe the key biological (therapeutic benefit and biocompatibility) and biomechanical (degradability, adhesive strength, stiffness, viscoelasticity, tunability and self-healing capacity) characteristics that are essential for an ideal lung bio-adhesive material with the potential to overcome the concerns related to current adhesives.</p
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