Citations

The neuropathological hallmarks of Alzheimer’s disease (AD) are senile plaques (SPs), which are composed of amyloid β protein (Aβ), and neurofibrillary tangles (NFTs), which consist of highly phosphorylated tau protein. As bio-metal imbalance may be involved in the formation of NFT and SPs, metal regulation may be a direction for AD treatment. Clioquinol (CQ) is a metal-protein attenuating compound with mild chelating effects for Zn2+ and Cu2+, and CQ can not only detach metals from SPs, but also decrease amyloid aggregation in the brain. Previous studies suggested that Cu2+ induces the hyperphosphorylation of tau. However, the effects of CQ on tau were not fully explored. To examine the effects of CQ on tau metabolism, we used a human neuroblastoma cell line, M1C cells, which express wild-type tau protein (4R0N) via tetracycline-off (TetOff) induction. In a morphological study and ATP assay, up to 10 μM CQ had no effect on cell viability; however, 100 μM CQ had cytotoxic effects. CQ decreased accumulation of Cu+ in the M1C cells (39.4% of the control), and both total and phosphorylated tau protein. It also decreased the activity of c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38 MAPK) (37.3% and 60.7% levels of the control, respectively), which are tau kinases. Of note, activation of protein phosphatase 2A (PP2A), which is a tau phosphatase, was also observed after CQ treatment. Fractionation experiments demonstrated a reduction of oligomeric tau in the tris insoluble, sarkosyl soluble fraction by CQ treatment. CQ also decreased caspase-cleaved tau, which accelerated the aggregation of tau protein. CQ activated autophagy and proteasome pathways, which are considered important for the degradation of tau protein. Although further studies are needed to elucidate the mechanisms responsible for the effects of CQ on tau, CQ may shed light on possible AD therapeutics.

Significance Phase separation of proteins is increasingly thought to play a fundamental role in biological processes. Recent studies show that tau protein phase separates, but the biological significance is unknown since artificial crowding agents are typically used and the resulting tau is not toxic. We now demonstrate that TIA1 potentiates RNA-mediated phase separation of tau, thereby enabling a process that occurs at physiological concentrations and also directs the formation of biologically active, highly neurotoxic oligomeric tau. Coordinated phase separation of functionally related proteins provides a general mechanism through which membraneless organelles can direct biological activities.

AbstractBackgroundThe pathological features of AD are neurofibrillary tangles (NFTs) composed of highly phosphorylated tau and senile plaques (SPs) composed of amyloid β protein (Aβ). It was suggested that Cu2 + induced hyperphosphorylation of tau and Zn2 + deposits on SPs. Clioquinol (CQ) has a mild chelating effect on Zn2 + and Cu2 +. In addition, CQ has been shown to reduce Aβ aggregation by removing Zn2+ from SPs. However, the effect of CQ on tau aggregation is not fully understood. The purpose of our study is to examine the effect of CQ on tau metabolism by using a cell culture model of tauopathy.MethodsHuman neuroblastoma cell line M1C cells that express wild‐type tau protein (4R0N) via tetracycline (Tet) off induction was used. M1C cells were exposed to 0.1‐10 μM CQ on day 4 of Tet‐Off induction, and harvested at the end of Day 5. Total tau detected by Tau5, and phosphorylated tau detected by PS199/202, AT180, AT270, CP13, and PHF‐1 antibodies, were examined using Western blot analysis. Immunocytochemical studies, fractional analysis and immunoprecipitation of ubiquitinated tau were also performed. Tau kinases including c‐Jun N‐terminal kinase (JNK), and P38 MAPK and tau phosphatase, protein phosphatase 2A (PP2A) were also examined. C‐terminal truncated pathological tau was detected by using the antibody TauC3. In addition, autophagy and proteasome activity were also examined.ResultPhosphorylated tau levels were reduced by 1‐10 μM CQ treatment. Tau kinases, JNK and p38 MAPK were inactivated by CQ treatment. Interestingly, activation of the tau phosphatase PP2A was also observed with CQ treatment. Fractionation studies showed that CQ treatment reduced AT180 and AT270 positive high molecular weight tau in the Tris‐insoluble, sarkosyl‐soluble fraction. CQ also reduced tau oligomer specific antibody TOC1‐positive oligomeric tau. CQ reduced caspase‐cleaved tau detected by antibody TauC3. P62 levels were reduced by CQ treatment, suggesting that CQ activates autophagy. In addition, CQ slightly reduced high molecular weight ubiquitinated tau. This implies activation of the ubiquitin‐proteasome by CQ.ConclusionCQ could provide beneficial effects against pathogenic forms of tau via multiple mechanisms and may represent a viable therapeutic approach for AD and other tauopathies.

AbstractBackgroundNeurofibrillary tangle (NFT), composed of highly phosphorylated tau is one of the pathological hallmarks of Alzheimer’s disease (AD). Spleen tyrosine kinase (Syk) is non receptor type tyrosine kinase, and has various physiological functions, including histamine release in mast cells, phagocytosis in macrophage, and B cell differentiation. The possibility of Syk inhibitor for clinical application was proposed in allergic rhinitis, rheumatoid arthritis, and immunologic thrombocytopenia. The possible relationship between Syk and AD has been reported recently. We have examined the effects of Syk specific inhibitor BAY61‐3606 on phosphorylation levels of tau protein and oligomeric tau by using cell culture model of tauopathy, M1C cells.MethodsWe utilized human neuroblastoma cell line M1C cells, which expresses wild type tau protein (4R0N) via tetracycline off induction (Tet Off induction). Reduction of phosphorylated tau protein and oligomeric tau protein by Syk inhibitor was examined by using various phospho‐tau antibodies, and tau oligomer specific antibody. Influences of activity of autophagy by Syk inhibitor was also examined by western blot analysis.ResultsIn this cell line, 72kDa of Syk protein was identified by Western blot analysis. Phosphorylated tau detected by various phospho‐tau antibodies, including PHF‐1, CP13, and AT270 was decreased by 1, 10 μM of Syk inhibitor. One of the patholoigical form of tau, caspase cleaved tau detected by TauC3 was also decreased by Syk inhibitor. Oligomeric tau, which detected by tau oligomer specific antibody, TOC1 was also decreased by Syk inhibitor. Syk inhibitor also inactivated glycogen synthase kinase 3β (GSK3β). Syk inhibitor upregulated autophagy detected by increase of LC3‐II, and reduction of P62. In summary, Syk inhibitor decreased phosphorylated tau as well as total tau by upregulating autophagy, and inactivating tau kinases, including GSK3β. Finally, oligomeric tau was reduced by Syk inhibitor.ConclusionSyk inhibitor may have promising for the treatment of tauopathy, including AD.

Abstract Introduction: Amplification of chromosome 9p24.1 encoding PDL1, PDL2, and JAK2 (the PDJ amplicon) has been detected in 5-25% of triplenegative breast cancers (TNBC), and is associated with poor outcome and activation of the JAK/STAT pathway. Here, we have developed a robust multiplexed fluorescence in situ hybridization (FISH) assay for detection of 9p24.1 amplification, and assessed the frequency and cellular distribution of the PDJ amplicon in a cohort of African American (AA) women with TNBC. Methods: The FISH assay combines three chromosome 9 probes to simultaneously target JAK2 and PD-L1 (9p24.1, PDJ), chromosome 9q22, and the 9q34.1 regions. This enables discrimination of PDJ amplicons from whole chromosome 9p arm gains and from chromosome 9 ploidies that occur in the background of genomic instability in aneuploid cancer genomes. Fifty cells were scored for each probe and the average copy number was obtained. We defined PDJ amplification as PDJ>4, PDJ/9q22 ratio≥2, and/or PDJ/9q34.1 ratio≥2. The assay was benchmarked to array CGH of flow sorted TNBC tissue from Mayo Clinic Arizona (n=14). Tissue microarrays from TNBC PDX tumors (n=20) and from African American women with TNBC (n=87) were assessed. Results: Using selected TNBC tissue with known CGH data, the FISH assay tightly correlated with PDJ copy number in 13/14 cases. The discordant case was negative by CGH on a biopsy with low tumor content, but FISH positive on tissue section (PDJ >7.5 and a PDJ/9q22 ratio=4). Of 20 TNBC PDX tumors, 5 were amplified by FISH. Twelve of 87 (14%) of tumors had PDJ amplification by FISH, of which ten were from breast tissue and two were from lymph node. Of these 12, PDJ>4 (n=0), PDJ/9q22 ratio≥2 (n=6), and PDJ/9q34.1 ratio≥2 (n=10). Significant intratumoral variation was observed with the presence of single cells with >10 PDJ copies in 8/17 (47%) amplified and 0/90 non-amplified total cases. Conclusion: 9p24.1 (PDJ) amplification encoding JAK2, PD-L1, and PD-L2 is detected by three-color FISH in 14% of TNBC from African American women. Individual cells with ≥10 copies of PDJ was seen exclusively in 8/17 amplified cases. We identified 5 PDX tumors which may provide valuable preclinical models for the amplicon. The association of this biomarker with clinical outcome will be presented. Citation Format: Karen S. Anderson, Tammey Naab, Lori K Koslosky, Megan Anderson, Michael Lewis, Yasmine Kanaan, Ali Afsari, Luisel Ricks-Santi, Barbara A. Pockaj, Michael T Barrett. Tissue prevalence and cellular heterogeneity of 9p24.1 amplification in TNBC in African American women [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-10-17.

Abstract BACKGROUND Aneurysm recurrence after coiling has been associated with aneurysm growth, (re)hemorrhage, and a greater need for follow-up. The second-generation HydroCoil Embolic System (HES; MicroVention, Inc) consists of a platinum core with integrated hydrogel and was developed to reduce recurrence through enhancing packing density and healing within the aneurysm. OBJECTIVE To compare recurrence between the second-generation HES and bare platinum coil (BPC) in the new-generation Hydrogel Endovascular Aneurysm Treatment Trial (HEAT). METHODS HEAT is a randomized, controlled trial that enrolled subjects with ruptured or unruptured 3- to 14-mm intracranial aneurysms amenable to coiling. The primary endpoint was aneurysm recurrence using the Raymond-Roy scale. Secondary endpoints included minor and major recurrence, packing density, adverse events related to the procedure and/or device, mortality, initial complete occlusion, aneurysm retreatment, hemorrhage from target aneurysm during follow-up, aneurysm occlusion stability, and clinical outcome at final follow-up. RESULTS A total of 600 patients were randomized (HES, n = 297 and BPC, n = 303), including 28% with ruptured aneurysms. Recurrence occurred in 11 (4.4%) subjects in the HES arm and 44 (15.4%) subjects in the BPC arm ( P = .002). While the initial occlusion rate was higher with BPC, the packing density and both major and minor recurrence rates were in favor of HES. Secondary endpoints including adverse events, retreatment, hemorrhage, mortality, and clinical outcome did not differ between arms. CONCLUSION Coiling of small-to-medium aneurysms with second-generation HES resulted in less recurrence when compared to BPC, without increased harm. These data further support the use of the second-generation HES for the embolization of intracranial aneurysms. Video Abstract

Objective: We sought to describe contemporary presentation, treatment, and outcomes of patients presenting with acute (A), perforated (P), and gangrenous (G) appendicitis in the United States. Summary Background Data: Recent European trials have reported that medical (antibiotics only) treatment of acute appendicitis is an acceptable alternative to surgical appendectomy. However, the type of operation (open appendectomy) and average duration of stay are not consistent with current American practice and therefore their conclusions do not apply to modern American surgeons. Methods: This multicenter prospective observational study enrolled adults with appendicitis from January 2017 to June 2018. Descriptive statistics were performed. P and G were combined into a “complicated” outcome variable and risk factors were assessed using multivariable logistic regression. Results: A total 3597 subjects were enrolled across 28 sites: median age was 37 (27–52) years, 1918 (53%) were male, 90% underwent computed tomography (CT) imaging, 91% were initially treated by appendectomy (98% laparoscopic), and median hospital stay was 1 (1–2) day. The 30-day rates of Emergency Department (ED) visit and readmission were 10% and 6%. Of 219 initially treated with antibiotics, 35 (16%) required appendectomy during index hospitalization and 12 (5%) underwent appendectomy within 30 days, for a cumulative failure rate of 21%. Overall, 2403 (77%) patients had A, whereas 487 (16%) and 218 (7%) patients had P and G, respectively. On regression analysis, age, symptoms >48 hours, temperature, WBC, Alvarado score, and appendicolith were predictive of “complicated” appendicitis, whereas co-morbidities, smoking, and ED triage to appendectomy >6 hours or >12 hours were not. Conclusion: In the United States, the majority of patients presenting with appendicitis receive CT imaging, undergo laparoscopic appendectomy, and stay in the hospital for 1 day. One in five patients selected for initial non-operative management required appendectomy within 30 days. In-hospital delay to appendectomy is not a risk factor for “complicated” appendicitis.