TY - JOUR
T1 - Islet amyloid polypeptide (iapp)
T2 - A second amyloid in alzheimer’s disease
AU - Fawver, Janelle N.
AU - Ghiwot, Yonatan
AU - Koola, Catherine
AU - Carrera, Wesley
AU - Rodriguez-Rivera, Jennifer
AU - Hernandez, Caterina
AU - Dineley, Kelly T.
AU - Kong, Yu
AU - Li, Jianrong
AU - Jhamandas, Jack
AU - Perry, George
AU - Murray, Ian V.J.
PY - 2014/12/1
Y1 - 2014/12/1
N2 - Amyloid formation is the pathological hallmark of type 2 diabetes (T2D) and Alzheimer’s disease (AD). These diseases are marked by extracellular amyloid deposits of islet amyloid polypeptide (IAPP) in the pancreas and amyloid _ (A_) in the brain. Since IAPP may enter the brain and disparate amyloids can cross-seed each other to augment amyloid formation, we hypothesized that pancreatic derived IAPP may enter the brain to augment misfolding of A_ in AD. The corollaries for validity of this hypothesis are that IAPP [1] enters the brain, [2] augments A_ misfolding, [3] associates with A_ plaques, and most importantly [4] plasma levels correlate with AD diagnosis. We demonstrate the first 3 corollaries that: (1) IAPP is present in the brain in human cerebrospinal fluid (CSF), (2) synthetic IAPP promoted oligomerization of A_ in vitro, and (3) endogenous IAPP localized to A_ oligomers and plaques. For the 4th corollary, we did not observe correlation of peripheral IAPP levels with AD pathology in either an African American cohort or AD transgenic mice. In the African American cohort, with increased risk for both T2D and AD, peripheral IAPP levels were not significantly different in samples with no disease, T2D, AD, or both T2D and AD. In the Tg2576 AD mouse model, IAPP plasma levels were not significantly elevated at an age where the mice exhibit the glucose intolerance of pre-diabetes. Based on this negative data, it appears unlikely that peripheral IAPP cross-seeds or “infects” A_ pathology in AD brain. However, we provide novel and additional data which demonstrate that IAPP protein is present in astrocytes in murine brain and secreted from primary cultured astrocytes. This preliminary report suggests a potential and novel association between brain derived IAPP and AD, however whether astrocytic derived IAPP cross-seeds A_ in the brain requires further research.
AB - Amyloid formation is the pathological hallmark of type 2 diabetes (T2D) and Alzheimer’s disease (AD). These diseases are marked by extracellular amyloid deposits of islet amyloid polypeptide (IAPP) in the pancreas and amyloid _ (A_) in the brain. Since IAPP may enter the brain and disparate amyloids can cross-seed each other to augment amyloid formation, we hypothesized that pancreatic derived IAPP may enter the brain to augment misfolding of A_ in AD. The corollaries for validity of this hypothesis are that IAPP [1] enters the brain, [2] augments A_ misfolding, [3] associates with A_ plaques, and most importantly [4] plasma levels correlate with AD diagnosis. We demonstrate the first 3 corollaries that: (1) IAPP is present in the brain in human cerebrospinal fluid (CSF), (2) synthetic IAPP promoted oligomerization of A_ in vitro, and (3) endogenous IAPP localized to A_ oligomers and plaques. For the 4th corollary, we did not observe correlation of peripheral IAPP levels with AD pathology in either an African American cohort or AD transgenic mice. In the African American cohort, with increased risk for both T2D and AD, peripheral IAPP levels were not significantly different in samples with no disease, T2D, AD, or both T2D and AD. In the Tg2576 AD mouse model, IAPP plasma levels were not significantly elevated at an age where the mice exhibit the glucose intolerance of pre-diabetes. Based on this negative data, it appears unlikely that peripheral IAPP cross-seeds or “infects” A_ pathology in AD brain. However, we provide novel and additional data which demonstrate that IAPP protein is present in astrocytes in murine brain and secreted from primary cultured astrocytes. This preliminary report suggests a potential and novel association between brain derived IAPP and AD, however whether astrocytic derived IAPP cross-seeds A_ in the brain requires further research.
KW - Alzheimer's disease
KW - Amylin
KW - Amyloid beta
KW - Blood
KW - Brain
KW - Immunohistochemistry
KW - Metabolic dysfunction
KW - Oligomers
KW - Plaques
KW - Type 2 diabetes
UR - http://www.scopus.com/inward/record.url?scp=84919630921&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84919630921&partnerID=8YFLogxK
U2 - 10.2174/1567205011666141107124538
DO - 10.2174/1567205011666141107124538
M3 - Article
C2 - 25387341
AN - SCOPUS:84919630921
SN - 1567-2050
VL - 11
SP - 928
EP - 940
JO - Current Alzheimer Research
JF - Current Alzheimer Research
IS - 10
ER -