Faculty Bibliography

Accumulation of phosphorylated tau is a key pathological feature of Alzheimer's disease. Phosphorylated tau accumulation causes synaptic impairment, neuronal dysfunction and formation of neurofibrillary tangles. The pathological actions of phosphorylated tau are mediated by surrounding neuronal proteins; however, a comprehensive understanding of the proteins that phosphorylated tau interacts with in Alzheimer's disease is surprisingly limited. Therefore, the aim of this study was to determine the phosphorylated tau interactome. To this end, we used two complementary proteomics approaches: (i) quantitative proteomics was performed on neurofibrillary tangles microdissected from patients with advanced Alzheimer's disease; and (ii) affinity purification-mass spectrometry was used to identify which of these proteins specifically bound to phosphorylated tau. We identified 542 proteins in neurofibrillary tangles. This included the abundant detection of many proteins known to be present in neurofibrillary tangles such as tau, ubiquitin, neurofilament proteins and apolipoprotein E. Affinity purification-mass spectrometry confirmed that 75 proteins present in neurofibrillary tangles interacted with PHF1-immunoreactive phosphorylated tau. Twenty-nine of these proteins have been previously associated with phosphorylated tau, therefore validating our proteomic approach. More importantly, 34 proteins had previously been associated with total tau, but not yet linked directly to phosphorylated tau (e.g. synaptic protein VAMP2, vacuolar-ATPase subunit ATP6V0D1); therefore, we provide new evidence that they directly interact with phosphorylated tau in Alzheimer's disease. In addition, we also identified 12 novel proteins, not previously known to be physiologically or pathologically associated with tau (e.g. RNA binding protein HNRNPA1). Network analysis showed that the phosphorylated tau interactome was enriched in proteins involved in the protein ubiquitination pathway and phagosome maturation. Importantly, we were able to pinpoint specific proteins that phosphorylated tau interacts with in these pathways for the first time, therefore providing novel potential pathogenic mechanisms that can be explored in future studies. Combined, our results reveal new potential drug targets for the treatment of tauopathies and provide insight into how phosphorylated tau mediates its toxicity in Alzheimer's disease.

ADAMTSs (a disintegrin and metalloproteinase with thrombospondin motifs) are secreted metalloproteinases that play a major role in the assembly and degradation of the extracellular matrix (ECM). In this study, we show that ADAMTS18, produced by the epithelial cells of distal airways and mesenchymal cells in lung apex at early embryonic stages, serves as a morphogen in lung development. ADAMTS18 deficiency leads to reduced number and length of bronchi, tipped lung apexes, and dilated alveoli. These developmental defects worsen lipopolysaccharide-induced acute lung injury and bleomycin-induced lung fibrosis in adult Adamts18-deficient mice. ADAMTS18 deficiency also causes increased levels of fibrillin1 and fibrillin2, bronchial microfibril accumulation, decreased focal adhesion kinase signaling, and disruption of F-actin organization. Our findings indicate that ECM homeostasis mediated by ADAMTS18 is pivotal in airway branching morphogenesis.

Alzheimer's disease (AD) is a neurodegenerative brain disorder associated with relentlessly progressive cognitive impairment and memory loss. AD pathology proceeds for decades before cognitive deficits become clinically apparent, opening a window for preventative therapy. Imbalance of clearance and buildup of amyloid β and phosphorylated tau proteins in the central nervous system is believed to contribute to AD pathogenesis. However, multiple clinical trials of treatments aimed at averting accumulation of these proteins have yielded little success, and there is still no disease-modifying intervention. Here, we discuss current knowledge of AD pathology and treatment with an emphasis on emerging biomarkers and treatment strategies.

PURPOSE OF REVIEW/OBJECTIVE:Primary age-related tauopathy (PART) was recently proposed as a pathologic diagnosis for brains that harbor neurofibrillary tangles (Braak stage ≤ 4) with little, if any, amyloid burden. We sought to review the clinicopathologic findings related to PART. RECENT FINDINGS/RESULTS:Most adult human brains show at least focal tauopathic changes, and the majority of individuals with PART do not progress to dementia. Older age and cognitive impairment correlate with increased Braak stage, and multivariate analyses suggest that the rate of cognitive decline is less than matched patients with Alzheimer disease (AD). It remains unclear whether PART is a distinct tauopathic entity separate from AD or rather represents an earlier histologic stage of AD. Cognitive decline in PART is usually milder than AD and correlates with tauopathic burden. Biomarker and ligand-based radiologic studies will be important to define PART antemortem and prospectively follow its natural history.

BACKGROUND:We have described the clinical stages of the brain aging and Alzheimer's disease (AD) continuum. In terms of the pre-dementia stages of AD, we introduced the terminology "mild cognitive impairment" (MCI) for the first pre-dementia stage and "subjective cognitive decline" (SCD) for the pre-MCI stage. We now report the characteristics of a pre-SCD condition eventuating in likely AD. OBJECTIVE:The aim of this study was to characterize a pre-SCD condition eventuating in AD. METHOD/METHODS:Sixty healthy persons with "no cognitive decline" (NCD) were recruited and 47 were followed (mean baseline age, 64.1 ± 8.9 years; mean follow-up time, 6.7 ± 3.1 years). Outcome was determined at the final assessment prior to 2002 as "decliner," if SCD or worse, or "nondecliner" if NCD. RESULTS:After controlling for age, gender, years of education, and follow-up time, there was a between-group difference in the decline rate (p < 0.001). Also, after controlling for demographic variables and follow-up time, the combinatorial psychometric score was lower at baseline in the future decliners (p = 0.035). Of the 9 psychometric variables, after controlling for demographic variables and follow-up time, 3 were significantly lower at baseline in future decliners. Since AD is known to be age related and all subjects in this study were otherwise healthy, we also did an analysis without controlling for age. The combinatorial psychometric score was highly significantly better at baseline in the future nondecliners than in the future decliners (p = 0.008). CONCLUSION/CONCLUSIONS:This is ostensibly the first study to link psychometric cognitive decline to the subsequent SCD stage of eventual AD.

Purpose of Study Autism spectrum disorders (ASDs) are neurodevelopmental disorders with lifelong consequences and poorly understood pathophysiology. Dysregulated cholesterol metabolism is implicated in ASD etiology. Cholesterol is essential for neuroactive steroid production, myelin sheath formation, and normal brain development. Early postnatal or in utero exposure to the antiepileptic drug valproic acid (VPA), a branched short-chain fatty acid, causes autism-like neural and behavioral deficits in humans and rodents. This study examines the link between VPA and cholesterol deficit in cultured human neurons and microglia. Methods Used SHSY-5Y human neuroblastoma cells and HMC3 human microglial cells were exposed to VPA at 0, 250, 1000 and 5000 muM for 24h, N=3 per condition. Expression of critical genes that regulate cholesterol transport were quantified by RT-PCR using specific primers for each. These include the efflux proteins ABCA1, ABCG1, 27-hydroxylase (27-OHase) and 24-hydroxylase (24-OHase), and the influx scavenger receptor CD36 - all vital for brain cholesterol balance. Expression of these target genes was normalized to concurrently measured GAPDH mRNA levels. Summary of Results In SH-SY5Y neurons, VPA exposure caused a concentration-dependent increase in ABCA1 (P <0.001), ABCG1, 27-OHase (P <0.001) (figure 1), and CD36 (P=0.015). In HMC3, VPA exposure caused a concentration- dependent increase in ABCG1 (80-fold at highest dose, P<=0.001) and 24-OHase (P < 0.001) with a reduction in ABCA-1 (P=0.002) and an increase in CD36 (P<0.001). Conclusions This study shows that VPA has a dramatic hypocholesterolemic effect on two key cell types that compose the developing brain. The net impact of the changes observed in these cholesterol-related genes would be outflow and metabolism. Further, enhanced 27-OHase activity produces an oxysterol metabolite with neurotoxic effects that include downregulating synaptic proteins and decreasing neurite number and length. Together, our results suggest that VPA impairs brain cholesterol homeostasis. A better understanding of the involvement of cholesterol in the mechanisms by which VPA leads to ASDs may translate into novel preventative therapies for this serious disorder

Background: Alzheimer's disease (AD) is a progressive neurodegenerative disease that currently accounts for over 70% of cases of dementia in adults over 65 worldwide, and is the only cause of death among the top ten with no effective treatments. Clinically, AD is characterized by progressive deterioration in memory and other areas of cognitive function. Neuropathologically, the disease is characterized by extracellular aggregations of amyloid-B (AB) and intraneuronal neurofibrillary tangles (NFTS) composed of abnormally phosphorylated tau, causing progressive neuronal death. The aim of this study was to investigate whether the affibody ZSYM73-ABD (a portion of the active antibody molecule) can reverse AD pathology in an AD mouse model, without also causing significant neuroinflammation and/or microhemorrhage.
Method(s): APP/PS1 double transgenic mice were injected twice weekly with either ZSYM-ABD or a non-AB specific affibody, Ztaq2, as a control. Mice underwent behavioral testing and their brains were then sacrificed for immunohistochemistry.
Result(s): Semi-quantitative analysis of amyloid burden, performed using 6E10/4G8 antibodies, showed a statistically significant reduction in amyloid burden in the hippocampus, and a trend towards reduction in amyloid burden in the cortex. Inflammation was assessed using GFAP and Iba1(markers of gliosis) which showed a statistically significant reduction of GFAP in the cortex and in the hippocampus, and a slight reduction of microgliosis in ZSYM73-ABD affibody treated mice. Finally, mice treated with ZSYM73-ABD performed significantly better on a novel object recognition task than control mice, suggesting a correlation between the histological findings above and improvement in cognitive function.
Conclusion(s): In conclusion, this study demonstrates that passive immunization with an affibody molecule improves cognitive function and significantly decreases amyloid burden in the hippocampus of a transgenic mouse model of AD, without inducing inflammation. This has potential implications for treatment of AD in humans

Biochirality is the subject of distinct branches of science, including biophysics, biochemistry, the stereochemistry of protein folding, neuroscience, brain functional laterality and bioinformatics. At the protein level, biochirality is closely associated with various post-translational modifications (PTMs) accompanied by the non-equilibrium phase transitions (PhTs ^NE). PTMs ^NE support the dynamic balance of the prevalent chirality of enzymes and their substrates. The stereoselective nature of most biochemical reactions is evident in the enzymatic (Enz) and spontaneous (Sp) PTMs (PTMs ^Enz and PTMs ^Sp) of proteins. Protein chirality, which embraces biophysics and biochemistry, is a subject of this review. In this broad field, we focus attention to the amyloid-beta (Aβ) peptide, known for its essential cellular functions and associations with neuropathology. The widely discussed amyloid cascade hypothesis (ACH) of Alzheimer's disease (AD) states that disease pathogenesis is initiated by the oligomerization and subsequent aggregation of the Aβ peptide into plaques. The racemization-induced aggregation of protein and RNA have been extensively studied in the search for the contribution of spontaneous stochastic stereo-specific mechanisms that are common for both kinds of biomolecules. The failure of numerous Aβ drug-targeting therapies requires the reconsolidation of the ACH with the concept of PTMs ^Sp. The progress in methods of chiral discrimination can help overcome previous limitations in the understanding of AD pathogenesis. The primary target of attention becomes the network of stereospecific PTMs that affect the aggregation of many pathogenic agents, including Aβ. Extensive recent experimental results describe the truncated, isomerized and racemized forms of Aβ and the interplay between enzymatic and PTMs ^Sp. Currently, accumulated data suggest that non-enzymatic PTMs ^Sp occur in parallel to an existing metabolic network of enzymatic pathways, meaning that the presence and activity of enzymes does not prevent non-enzymatic reactions from occurring. PTMs ^Sp impact the functions of many proteins and peptides, including Aβ. This is in logical agreement with the silently accepted racemization hypothesis of protein aggregation (RHPA). Therefore, the ACH of AD should be complemented by the concept of PTMs ^Sp and RHPA.

Sudden unexplained death in childhood (SUDC) affects children >1-year-old whose cause of death remains unexplained following comprehensive case investigation and is often associated with hippocampal abnormalities. We prospectively performed systematic neuropathologic investigation in 20 SUDC cases, including (i) autopsy data and comprehensive ancillary testing, including molecular studies, (ii) ex vivo 3T MRI and extensive histologic brain samples, and (iii) blinded neuropathology review by 2 board-certified neuropathologists. There were 12 girls and 8 boys; median age at death was 33.3 months. Twelve had a history of febrile seizures, 85% died during apparent sleep and 80% in prone position. Molecular testing possibly explained 3 deaths and identified genetic mutations in TNNI3, RYR2, and multiple chromosomal aberrations. Hippocampal abnormalities most often affected the dentate gyrus (altered thickness, irregular configuration, and focal lack of granule cells), and had highest concordance between reviewers. Findings were identified with similar frequencies in cases with and without molecular findings. Number of seizures did not correlate with hippocampal findings. Hippocampal alterations were the most common finding on histological review but were also found in possibly explained deaths. The significance and specificity of hippocampal findings is unclear as they may result from seizures, contribute to seizure pathogenesis, or be an unrelated phenomenon.

INTRODUCTION/BACKGROUND:After infection, herpes simplex virus-1 (HSV1) becomes latent in the trigeminal ganglion and can enter the brain via retrograde axonal transport. Recurrent reactivation of HSV1 may lead to neurodegeneration and Alzheimer's disease (AD) pathology. HSV1 (oral herpes) and HSV2 (genital herpes) can trigger amyloid beta-protein (Aβ) aggregation and HSV1 DNA is common in amyloid plaques. Anti-HSV drugs reduce Aβ and phosphorylated tau accumulation in cell-culture models. Cognitive impairment is greater in patients with HSV seropositive, and antiviral drugs show robust efficacy against peripheral HSV infection. Recent studies of electronic health records databases demonstrate that HSV infections increase dementia risk, and that antiviral medication treatment reduces this risk. The generic antiviral drug valacyclovir was superior to placebo in improving memory in a schizophrenia pilot trial but has not been tested in AD. METHODS AND ANALYSIS/UNASSIGNED:F-MK-6240 PET imaging, to show less amyloid and tau accumulation, respectively. In the lumbar puncture subsample, cerebrospinal fluid acyclovir will be assayed to assess central nervous system valacyclovir penetration. ETHICS AND DISSEMINATION/UNASSIGNED:The trial is being overseen by the New York State Psychiatric Institute Institutional Review Board (protocol 7537), the National Institute on Ageing, and the Data Safety Monitoring Board. Written informed consent is obtained for all subjects. Results will be disseminated via publication, clinicaltrials.gov, media and conferences. TRIAL REGISTRATION NUMBER/BACKGROUND:ClinicalTrials.gov identifier (NCT03282916) Pre-results.