scholarly journals Deformability-based microfluidic separation of pancreatic islets from exocrine acinar tissue for transplant applications

Lab on a Chip ◽  
2017 ◽  
Vol 17 (21) ◽  
pp. 3682-3691 ◽  
Author(s):  
Walter B. Varhue ◽  
Linda Langman ◽  
Molly Kelly-Goss ◽  
Morgan Lataillade ◽  
Kenneth L. Brayman ◽  
...  
Keyword(s):  
Pancreatic Islets ◽  
High Throughput ◽  
Hydrodynamic Resistance ◽  
Microfluidic Separation ◽  
Acinar Tissue ◽  
Periodic Switching

Tangential flows for selective deformation of acinar tissue and periodic switching of hydrodynamic resistance enables high-throughput islet enrichment in transplant samples.

scholarly journals High-Throughput Approaches onto Uncover (Epi)Genomic Architecture of Type 2 Diabetes

Genes ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 374 ◽  
Author(s):  
Anna Dziewulska ◽  
Aneta Dobosz ◽  
Agnieszka Dobrzyn
Keyword(s):  
Type 2 Diabetes ◽  
Pancreatic Islets ◽  
High Throughput ◽  
Target Genes ◽  
Association Studies ◽  
Genome Wide Association Studies ◽  
Genomic Landscape ◽  
A Genome ◽  
Next Generation Sequencing Ngs

Type 2 diabetes (T2D) is a complex disorder that is caused by a combination of genetic, epigenetic, and environmental factors. High-throughput approaches have opened a new avenue toward a better understanding of the molecular bases of T2D. A genome-wide association studies (GWASs) identified a group of the most common susceptibility genes for T2D (i.e., TCF7L2, PPARG, KCNJ1, HNF1A, PTPN1, and CDKAL1) and illuminated novel disease-causing pathways. Next-generation sequencing (NGS)-based techniques have shed light on rare-coding genetic variants that account for an appreciable fraction of T2D heritability (KCNQ1 and ADRA2A) and population risk of T2D (SLC16A11, TPCN2, PAM, and CCND2). Moreover, single-cell sequencing of human pancreatic islets identified gene signatures that are exclusive to α-cells (GCG, IRX2, and IGFBP2) and β-cells (INS, ADCYAP1, INS-IGF2, and MAFA). Ongoing epigenome-wide association studies (EWASs) have progressively defined links between epigenetic markers and the transcriptional activity of T2D target genes. Differentially methylated regions were found in TCF7L2, THADA, KCNQ1, TXNIP, SOCS3, SREBF1, and KLF14 loci that are related to T2D. Additionally, chromatin state maps in pancreatic islets were provided and several non-coding RNAs (ncRNA) that are key to T2D pathogenesis were identified (i.e., miR-375). The present review summarizes major progress that has been made in mapping the (epi)genomic landscape of T2D within the last few years.

scholarly journals Immunohistochemical Localization of Somatostatin Receptor sst2A in Human Pancreatic Islets

1998 ◽  
Vol 83 (10) ◽  
pp. 3746-3749 ◽  
Author(s):  
J. C. Reubi ◽  
A. Kappeler ◽  
B. Waser ◽  
A. Schonbrunn ◽  
J. Laissue
Keyword(s):  
Pancreatic Islets ◽  
Islet Cells ◽  
Somatostatin Receptor ◽  
Somatostatin Receptors ◽  
Exocrine Secretion ◽  
Pancreatic Tissue ◽  
Receptor Subtype ◽  
Human Pancreas ◽  
Specific Staining ◽  
Acinar Tissue

Somatostatin and octreotide inhibit endocrine pancreatic functions in man, via specific somatostatin receptors. However, the cellular distribution of the different somatostatin receptor subtype proteins has not been determined in the human pancreas. Here, the immunohistochemical distribution of the sst2A receptor was investigated using the sst2A receptor specific anti-peptide antibody R2-88 in cryostat as well as in formalin-fixed paraffin-embedded sections of human pancreatic tissue, and compared with insulin, glucagon and somatostatin immunostaining of adjacent sections. All pancreatic islets were immunostained with R2-88. Most islet cells were labeled: the sst2A receptors were present in insulin as well as glucagon producing cells, but were not detected in intra-islet vessels nor in adjacent acinar tissue. Absorption of the sst2A antibody with 100 nM of the antigen peptide abolished specific staining in tissue sections. Immunohistochemical staining with 125I-Tyr3-octreotide. Therefore, the clinical efficacy of octreotide on glucagon and insulin release can be explained by the presence of sst2A receptors in human A and B pancreatic islet cells. Moreover, absence of sst2A receptors in human acinar tissue suggests that the action of somatostatin on pancreatic exocrine secretion is mediated either indirectly or through a different somatostatin receptor subtype on acinar cells.

scholarly journals Otubain 2 is a novel promoter of beta cell survival as revealed by siRNA high-throughput screens of human pancreatic islets

Diabetologia ◽  
2013 ◽  
Vol 56 (6) ◽  
pp. 1317-1326 ◽  
Author(s):  
A. Beck ◽  
Y. Vinik ◽  
H. Shatz-Azoulay ◽  
R. Isaac ◽  
S. Streim ◽  
...  
Keyword(s):  
Beta Cell ◽  
Cell Survival ◽  
Pancreatic Islets ◽  
High Throughput ◽  
Human Pancreatic Islets ◽  
High Throughput Screens

scholarly journals Interference-free Micro/nanoparticle Cell Engineering by Use of High-Throughput Microfluidic Separation

2015 ◽  
Vol 7 (37) ◽  
pp. 20855-20864 ◽  
Author(s):  
David C. Yeo ◽  
Christian Wiraja ◽  
Yingying Zhou ◽  
Hui Min Tay ◽  
Chenjie Xu ◽  
...  
Keyword(s):  
High Throughput ◽  
Cell Engineering ◽  
Microfluidic Separation

SIMULTANEOUS DETERMINATION OF THE CONTENT OF SEROTONIN, DOPAMINE, NORADRENALINE AND ADRENALINE IN PANCREATIC ISLETS ISOLATED FROM FED AND STARVED MICE

1977 ◽  
Vol 86 (4) ◽  
pp. 820-832 ◽  
Author(s):  
S. E. Hansen ◽  
C. J. Hedeskov
Keyword(s):  
Pancreatic Islets ◽  
Biogenic Amines ◽  
Simultaneous Determination ◽  
Isotope Method ◽  
Highly Sensitive ◽  
Wet Weight ◽  
Acinar Tissue ◽  
Noradrenaline And Adrenaline ◽  
Double Isotope

ABSTRACT A highly sensitive double isotope method for the simultaneous determination of serotonin, dopamine, noradrenaline and adrenaline has been developed. Advantages and limitations of the method are discussed. The mentioned biogenic amines are all present in isolated pancreatic islet tissue from albino mice in concentrations ranging from approximately 5-30 μmol per kg wet weight (0.8–5 × 10−3 pmol/ng DNA). A somewhat higher content of these amines, especially dopamine, was found in pancreatic acinar tissue. The hypothesis that the impaired glucose-induced insulin secretion during starvation partly is caused by an increased content of biogenic amines in the pancreatic islets was not supported by our experiments which showed an unchanged islet content of these amines after 48 h starvation.

scholarly journals Nonenzymatic Cryogenic Isolation of Therapeutic Cells: Novel Approach for Enzyme-Free Isolation of Pancreatic Islets Using In Situ Cryopreservation of Islets and Concurrent Selective Freeze Destruction of Acinar Tissue

2014 ◽  
Vol 23 (11) ◽  
pp. 1365-1379 ◽  
Author(s):  
Michael J. Taylor ◽  
Simona C. Baicu
Keyword(s):  
Pancreatic Islets ◽  
Stimulation Index ◽  
Enzyme Digestion ◽  
Isolated Pancreatic Islets ◽  
Novel Approach ◽  
Glucose Challenge ◽  
Syto 13 ◽  
Residual Tissue ◽  
Acinar Tissue

Cell-based therapies, which all involve processes for procurement and reimplantation of living cells, currently rely upon expensive, inconsistent, and even toxic enzyme digestion processes. A prime example is the preparation of isolated pancreatic islets for the treatment of type 1 diabetes by transplantation. To avoid the inherent pitfalls of these enzymatic methods, we have conceptualized an alternative approach based on the hypothesis that cryobiological techniques can be used for differential freeze destruction of the pancreas (Px) to release islets that are selectively cryopreserved in situ. Pancreata were procured from juvenile pigs using approved procedures. The concept of cryoisolation is based on differential processing of the pancreas in five stages: 1) infiltrating islets in situ preferentially with a cryoprotectant (CPA) cocktail via antegrade perfusion of the major arteries; 2) retrograde ductal infusion of water to distend the acinar; 3) freezing the entire Px solid to lt; −160°C for storage in liquid nitrogen; 4) mechanically crushing and pulverizing the frozen Px into small fragments; 5) thawing the frozen fragments, filtering, and washing to remove the CPA. Finally, the filtered effluent (cryoisolate) was stained with dithizone for identification of intact islets and with Syto 13/PI for fluorescence viability testing and glucose-stimulated insulin release assessment. As predicted, the cryoisolate contained small fragments of residual tissue comprising an amorphous mass of acinar tissue with largely intact and viable (>90%) embedded islets. Islets were typically larger (range 50–500 μm diameter) than their counterparts isolated from juvenile pigs using conventional enzyme digestion techniques. Functionally, the islets from replicate cryoisolates responded to a glucose challenge with a mean stimulation index = 3.3 ± 0.7. An enzyme-free method of islet isolation relying on in situ cryopreservation of islets with simultaneous freeze destruction of acinar tissue is feasible and proposed as a new and novel method that avoids the problems associated with conventional collagenase digestion methods.

Plasmalemma localisation of inorganic phosphate in B cells pancreas

1978 ◽  
Vol 36 (2) ◽  
pp. 528-529
Author(s):  
F. B. P. Wooding ◽  
K. Pedley ◽  
N. Freinkel ◽  
R. M. C. Dawson
Keyword(s):  
Electron Microscope ◽  
B Cells ◽  
B Cell ◽  
Pancreatic Islets ◽  
High Glucose ◽  
Lead Acetate ◽  
Inorganic Phosphate ◽  
Slight Modification ◽  
Uranyl Acetate ◽  
Lead Phosphate

Freinkel et al (1974) demonstrated that isolated perifused rat pancreatic islets reproduceably release up to 50% of their total inorganic phosphate when the concentration of glucose in the perifusion medium is raised.Using a slight modification of the Libanati and Tandler (1969) method for localising inorganic phosphate by fixation-precipitation with glutaraldehyde-lead acetate we can demonstrate there is a significant deposition of lead phosphate (identified by energy dispersive electron microscope microanalysis) at or on the plasmalemma of the B cell of the islets (Fig 1, 3). Islets after incubation in high glucose show very little precipitate at this or any other site (Fig 2). At higher magnification the precipitate seems to be intracellular (Fig 4) but since any use of osmium or uranyl acetate to increase membrane contrast removes the precipitate of lead phosphate it has not been possible to verify this as yet.

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