Presentation Title

Determining Aggregation Propensity of Islet Amyloid Polypeptide in Diabetic and Nondiabetic Organisms

Faculty Mentor

Dr. David Moffet

Start Date

17-11-2018 9:30 AM

End Date

17-11-2018 9:45 AM

Location

C161

Session

Oral 2

Type of Presentation

Oral Talk

Subject Area

biological_agricultural_sciences

Abstract

The aggregation of human Islet Amyloid Polypeptide (hIAPP), which has 37 amino acids, appears to contribute to the etiology of Type 2 Diabetes. The aggregation of IAPP into proteinaceous oligomers, fibrils, and plaques, collectively called amyloid, is theorized to disrupt β-cell function and may ultimately lead to cellular apoptosis and widespread loss of pancreatic tissue. While the exact mechanism driving amyloid formation remains unknown, if IAPP aggregation into toxic amyloid promotes the pathophysiology of Type 2 Diabetes in humans, this phenomenon would likely play a similar role within other organisms known to develop the disease. In spite of the significant amount of research about the clinical presentation of Type 2 Diabetes in humans, no comprehensive study has been conducted to directly correlate IAPP aggregation propensity to the potential to develop Diabetes within other animals. Thus, in this study, we compared the aggregation propensity and cellular toxicity of naturally occurring IAPP variants from organisms known to, or not known to, develop Type 2 Diabetes. Overall, the species expressing amyloidogenic variants of IAPP were also the species described to develop Type 2 Diabetes, strengthening the link between IAPP amyloid aggregation and the progression of the disease.


Please note (not part of abstract): Our research team has worked closely with the research team of Dr. Luiza Nogaj, who is the wife of our faculty advisor, Dr. David Moffet. Dr. Nogaj’s team has completed in-vivo studies regarding the aggregative toxicity of various animal forms of IAPP in cell lines. Because of the similar goals and themes of our research projects, our team would be open to being in the same presentation group as Dr. Nogaj’s team to strengthen the implications of our results.

Summary of research results to be presented

Results were obtained via Thioflavin-T assays, dot-blots, circular dichroism, TANGO software, and atomic force microscopy imaging of IAPP fibers after 5-7 days of incubation at room temperature. Of all the organisms tested, IAPP variants from human, cat, dog, racoon, chicken, dolphin, seal, and horse were found to aggregate into amyloid; all of these species are known to develop Type 2 Diabetes. IAPP variants from rat, degu, guinea pig, cow, sheep, pig, and polar bear were not found to form amyloid; all of these species, except for Polar Bear, are not known to develop Type 2 Diabetes. This strong correlation between IAPP aggregation and ability to develop Type 2 Diabetes is congruent with the theory of amyloidogenicity as a component of the pathophysiology of the disease. In comparing the aggregating vs. non-aggregating IAPP sequences, no singular amino acid was identified as being directly responsible for driving amyloid formation. However, the unique presence of valine at position 8 in the aggregating chicken, horse, and racoon IAPP sequences (in contrast to alanine at position 8 in human and all other animal IAPP variants, except for cow) may present new avenues of inquiry regarding the role of this amino acid in amyloid formation.

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Nov 17th, 9:30 AM Nov 17th, 9:45 AM

Determining Aggregation Propensity of Islet Amyloid Polypeptide in Diabetic and Nondiabetic Organisms

C161

The aggregation of human Islet Amyloid Polypeptide (hIAPP), which has 37 amino acids, appears to contribute to the etiology of Type 2 Diabetes. The aggregation of IAPP into proteinaceous oligomers, fibrils, and plaques, collectively called amyloid, is theorized to disrupt β-cell function and may ultimately lead to cellular apoptosis and widespread loss of pancreatic tissue. While the exact mechanism driving amyloid formation remains unknown, if IAPP aggregation into toxic amyloid promotes the pathophysiology of Type 2 Diabetes in humans, this phenomenon would likely play a similar role within other organisms known to develop the disease. In spite of the significant amount of research about the clinical presentation of Type 2 Diabetes in humans, no comprehensive study has been conducted to directly correlate IAPP aggregation propensity to the potential to develop Diabetes within other animals. Thus, in this study, we compared the aggregation propensity and cellular toxicity of naturally occurring IAPP variants from organisms known to, or not known to, develop Type 2 Diabetes. Overall, the species expressing amyloidogenic variants of IAPP were also the species described to develop Type 2 Diabetes, strengthening the link between IAPP amyloid aggregation and the progression of the disease.


Please note (not part of abstract): Our research team has worked closely with the research team of Dr. Luiza Nogaj, who is the wife of our faculty advisor, Dr. David Moffet. Dr. Nogaj’s team has completed in-vivo studies regarding the aggregative toxicity of various animal forms of IAPP in cell lines. Because of the similar goals and themes of our research projects, our team would be open to being in the same presentation group as Dr. Nogaj’s team to strengthen the implications of our results.