Human Islet Phenotyping Program (HIPP)
The Human Islet Phenotyping Program (HIPP) was established per NIH mandate in the summer of 2016 and awarded to the Vanderbilt Diabetes Center after a peer-reviewed application process.
The goal of the HIPP initiative is to provide standardized assessment of IIDP-contracted human islet preparations to understand the relationship between islet phenotypic features and key donor characteristics.
Data Generated by HIPP
Data from a single donor sample
Data from a single donor sample
Data from a single donor sample
HIPP generated data include:
- Post-Shipment Purity
- Post-Shipment Viability
- Hormone Content
- Endocrine Cell Composition
- Endocrine and Acinar Cell Composition
Parallel functional assessment of insulin and glucagon secretion from each islet preparation is coupled with information about islet morphology, purity, viability, and composition, and overlaid with deidentified donor data.
Tabular and complementary visual data are currently available to the IIDP-affiliated Islet Isolation Centers and Investigators through the IIDP-HIPP interface from the IIDP Center and Investigator websites as well as for download from the Research Data Repository (RDR).
Islet Counting, Purity, & Viability
Islet morphology is visualized by high resolution imaging of unstained islet preparation followed by staining with Dithizone (DTZ – quantitative measurement of islet number and purity by cellSens algorithms) and Fluorescein Diacetate/Propidium Iodide (FDA/PI – qualitative assessment of islet purity).
Viability of highly purified islets is quantitatively determined by exclusion of Trypan Blue in dispersed islet cells.
Functional Analysis
Islet function in vitro is assessed by perifusion which integrates islet insulin and glucagon secretion with high temporal resolution. This allows simultaneous measurements of sequential responses of islet alpha and beta cells to multiple well-defined stimuli with either apposing (i.e., high glucose, epinephrine) or co-stimulatory effects (i.e., cAMP-evoked potentiation, KCl-mediated depolarization) on insulin and glucagon secretion. Hormone secretory outputs are normalized and quantified with respect to either islet cell volume (expressed in islet equivalents, IEQ) or total islet hormone content.
Histological Analysis
To integrate islet functional data and morphologic information, islet preparation is assessed by immunocytochemistry for islet endocrine cell composition and acinar cell component using a histological approach that takes advantage of islet immobilization in Collagen I gel and then processing immobilized islets for cryosections.
Repository
Stored Samples
Purified islets RNA & protein
Acinar tissue DNA
Blocks for repository
The considerable resources required to isolate human islets demand that the maximum information be collected from every preparation. HIPP collects and stores samples for possible future investigation as determined by the IIDP and NIDDK program officers.
The HIPP is managed by Dr. Marcela Brissova, also director of the Islet Procurement and Analysis Core at the Vanderbilt Diabetes Research and Training Center.