Implications of the prion-related Q/N domains in TDP-43 and FUS.

Amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) are clinically overlapping neurodegenerative disorders whose pathophysiology remains incompletely understood. ALS initiates in a discrete location, and typically progresses in a pattern consistent with spread of the degenerative process to involve neighboring regions of the motor system, although the basis of the apparent "spread" remains elusive. Recently mutations in two RNA binding proteins, TDP-43 and FUS, were identified in patients with familial ALS.

Interaction with polyglutamine aggregates reveals a Q/N-rich domain in TDP-43.

The identification of pathologic TDP-43 aggregates in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration, followed by the discovery of dominantly inherited point mutations in TDP-43 in familial ALS, have been critical insights into the mechanism of these untreatable neurodegenerative diseases. However, the biochemical basis of TDP-43 aggregation and the mechanism of how mutations in TDP-43 lead to disease remain enigmatic. In efforts to understand how TDP-43 alters its cellular localization in response to proteotoxic stress, we found that TDP-43 is sequestered into polyglutamine aggregates.

Amyloid-beta(1-42) fibrillar precursors are optimal for inducing tumor necrosis factor-alpha production in the THP-1 human monocytic cell line.

Pathological studies have determined that fibrillar forms of amyloid-beta protein (Abeta) comprise the characteristic neuritic plaques in Alzheimer's disease (AD). These studies have also revealed significant inflammatory markers such as activated microglia and cytokines surrounding the plaques. Although the plaques are a hallmark of AD, they are only part of an array of Abeta aggregate morphologies observed in vivo.

Oligomeric amyloid-beta(1-42) induces THP-1 human monocyte adhesion and maturation.

Amyloid-beta (Abeta) is a naturally occurring 40- or 42-residue peptide fragment with a primary role in Alzheimer's disease (AD). Aggregated Abeta accumulates as both dense core plaques and diffuse deposits in the brains of AD patients. Abeta plaques are surrounded by activated microglia, some of which are believed to be derived from peripheral blood monocytes that have infiltrated the central nervous system and differentiated into phagocytes in response to Abeta.

Toll-like receptors 2 and 4 mediate Abeta(1-42) activation of the innate immune response in a human monocytic cell line.

The primary molecules for mediating the innate immune response are the Toll-like family of receptors (TLRs). Recent work has established that amyloid-beta (Abeta) fibrils, the primary components of senile plaques in Alzheimer's disease (AD), can interact with the TLR2/4 accessory protein CD14. Using antibody neutralization assays and tumor necrosis factor alpha release in the human monocytic THP-1 cell line, we determined that both TLR2 and TLR4 mediated an inflammatory response to aggregated Abeta(1-42).