Structure-Based Discovery of a Novel Class of Small-Molecule Pure Antagonists of Integrin αVß3.

Inhibitors of integrin αVß3 have therapeutic promise for a variety of diseases. Most αVß3-targeting small molecules patterned after the RGD motif are partial agonists because they induce a high-affinity, ligand-binding conformation and prime the receptor to bind the ligand without an activating stimulus, in part via a charge-charge interaction between their aspartic acid carboxyl group and the metal ion in the metal-ion-dependent adhesion site (MIDAS). Building upon our previous studies on the related integrin αIIbß3, we searched for pure αVß3 antagonists that lack this typical aspartic acid carboxyl group and instead engage through direct binding to one of the coordinating residues of the MIDAS metal ion, specifically ß3 E220. By in silico screening of two large chemical libraries for compounds interacting with ß3 E220, we indeed discovered a novel molecule that does not contain an acidic carboxyl group and does not induce the high-affinity, ligand-binding state of the receptor. Functional and structural characterization of a chemically optimized version of this compound led to the discovery of a novel small-molecule pure αVß3 antagonist that (i) does not prime the receptor to bind the ligand and does not induce hybrid domain swing-out or receptor extension as judged by antibody binding and negative-stain electron microscopy, (ii) binds at the RGD-binding site as predicted by metadynamics rescoring of induced-fit docking poses and confirmed by a cryo-electron microscopy structure of the compound-bound integrin, and (iii) coordinates the MIDAS metal ion via a quinoline moiety instead of an acidic carboxyl group.

Rational Development of a Small-Molecule Activator of CK1γ2 That Decreases C99 and Beta-Amyloid Levels.

Alzheimer's disease (AD) is a debilitating neurodegenerative disorder characterized by the accumulation of ß-amyloid (Aß), C99, and Tau in vulnerable areas of the brain. Despite extensive research, current strategies to lower Aß levels have shown limited efficacy in slowing the cognitive decline associated with AD. Recent findings suggest that C99 may also play a crucial role in the pathogenesis of AD. Our laboratory has discovered that CK1γ2 phosphorylates Presenilin 1 at the γ-secretase complex, leading to decreased C99 and Aß levels. Thus, CK1γ2 activation appears as a promising therapeutic target to lower both C99 and Aß levels. In this study, we demonstrate that CK1γ2 is inhibited by intramolecular autophosphorylation and describe a high-throughput screen designed to identify inhibitors of CK1γ2 autophosphorylation. We hypothesize that these inhibitors could lead to CK1γ2 activation and increased PS1-Ser367 phosphorylation, ultimately reducing C99 and Aß levels. Using cultured cells, we investigated the impact of these compounds on C99 and Aß concentrations and confirmed that CK1γ2 activation effectively reduced their levels. Our results provide proof of concept that CK1γ2 is an attractive therapeutic target for AD. Future studies should focus on the identification of specific compounds that can inhibit CK1γ2 autophosphorylation and evaluate their efficacy in preclinical models of AD. These studies will pave the way for the development of novel therapeutics for the treatment of AD.

[(18)F]T807, a novel tau positron emission tomography imaging agent for Alzheimer's disease.

OBJECTIVE: We wished to develop a highly selective positron emission tomography (PET) imaging agent targeting PHF-tau in human Alzheimer's disease (AD) brains. METHODS: To screen potential tau binders, human AD brain sections were used as a source of native paired helical filament (PHF)-tau and Aß rather than synthetic tau aggregates or Aß fibrils generated in vitro to measure the affinity and selectivity of [(18)F]T807 to tau and Aß. Brain uptake and biodistribution of [(18)F]T807 in mice were also tested. RESULTS: In vitro autoradiography results show that [(18)F]T807 exhibits strong binding to PHF-tau-positive human brain sections. A dissociation constant (Kd) of [(18)F]T807 (14.6 nM) was measured using brain sections from the frontal lobe of AD patients. A comparison of autoradiography and double immunohistochemical staining of PHF-tau and Aß on adjacent sections demonstrated that [(18)F]T807 binding colocalized with immunoreactive PHF-tau pathology, but did not highlight Aß plaques. In vivo studies in mice demonstrated that [(18)F]T807 was able to cross the blood-brain barrier and washed out quickly. CONCLUSIONS: [(18)F]T807 demonstrates high affinity and selectivity to PHF-tau as well as favorable in vivo properties, making this a promising candidate as an imaging agent for AD.

Cost and outcomes of intercostal nerve cryoablation versus thoracic epidural following the Nuss procedure.

BACKGROUND: Pectus excavatum is the most common congenital chest wall abnormality, with the Nuss procedure being the most commonly performed repair. Pain control is the predominant factor in the postoperative treatment of these patients. This study aims to compare the cost and outcomes of intercostal nerve cryoablation (INC) and thoracic epidural (TE) in patients undergoing the Nuss procedure. METHODS: A retrospective chart review was conducted at our institution for all patients who underwent the Nuss procedure for pectus excavatum from 2002 to 2020. Patients were stratified by pain management strategy, INC vs. TE. Chi-square and Fisher's exact were used to compare categorical variables. Wilcoxon tests were used to evaluate continuous variables and costs. RESULTS: A total of 158 patients were identified. Of these, 80.4% (N = 127) were treated with epidural, while 19.6% (N = 31) were treated with intercostal nerve cryoablation. The INC group had lower rates of PCA use (35.5% vs. 93.7%, p < 0.001), lower total morphine milligram equivalent requirement (27.0 vs. 290.8, p < 0.001), and shorter length of stay (3.2 days vs. 5.3 days, p < 0.001) compared to the TE group. INC was also associated with longer operative times (153.0 min vs. 89.0 min, p < 0.001). The total hospitalization cost for the INC group was higher compared to the TE group ($24,742.5 vs $21,621.9, p = 0.001). CONCLUSIONS: In patients undergoing the Nuss procedure, compared to thoracic epidural, INC was associated with lower opioid use and shorter length of stay but at the cost of longer operative time and increased hospitalization cost. LEVEL OF EVIDENCE: Treatment Study, Level III.

Comparing Non-invasive Prenatal Testing With Invasive Testing for the Detection of Trisomy 21.

Background Non-invasive prenatal test (NIPT) is an intermediate step between serum screening and invasive diagnostic testing. It involves analysis of the cell-free fetal DNA (cffDNA) present in the maternal blood sample for determining the likelihood of fetal aneuploidy. Owing to its high sensitivity and specificity, NIPT has quickly gained popularity across the globe since its introduction to clinical practice, making it an attractive alternative to the available screening and diagnostic tests in use. Amniocentesis is currently the gold standard test for obtaining fetal DNA and diagnosing fetal trisomy prenatally, but it is invasive and has procedure-related adverse effects. This study aims to compare NIPT and amniocentesis in pregnancies screened positive for fetal trisomy. Material and methods This is an analytic cross-sectional prospective study conducted in the Department of Obstetrics & Gynecology, Patna Medical College and Hospital, for two and half years from December 2018 to June 2021. A total of 34 pregnant women screened positive for trisomy 21, attending the antenatal care outpatient department, in their second trimester, with their written consent, were enrolled in the study. Results Out of 34 pregnant patients, three refused NIPT and directly opted for amniocentesis. A total of 31 pregnant women have undergone NIPT. A total of 28 cases were positive for trisomy 21 on both NIPT and amniocentesis. The sensitivity of NIPT was 100% with the confidence interval being 87.66% to 100.00%. The specificity of NIPT was 100% with the confidence interval being 29.24% to 100.00%. Conclusion The high performance and effectiveness of NIPT are undeniable. Though the process by which this test has to be integrated into the clinical practice needs more study and should be determined with meticulous assessment.

Review of aerosolized hydrogen peroxide, vaporized hydrogen peroxide, and hydrogen peroxide gas plasma in the decontamination of filtering facepiece respirators.

BACKGROUND: Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to over 170?million cases worldwide with over 33.2?million cases and 594,000 deaths in the US alone as of May 31st, 2021. The pandemic has also created severe shortages of personal protective equipment, particularly of filtering facepiece respirators (FFRs). The Centers for Disease Control and Prevention (CDC) has issued recommendations to help conserve FFRs, as well as crisis standards, including four criteria required for decontamination of the traditionally single use respirators. This review is designed to provide an overview of the current literature on vaporized hydrogen peroxide (vHP), hydrogen peroxide gas plasma (HPGP), and aerosolized hydrogen peroxide (aHP) with respect to each of the four CDC decontamination criteria. METHODS: PubMed and Medrxiv were queried for relevant articles. All articles underwent a title and abstract screen as well as subsequent full text screen by two blinded reviewers if indicated. RESULTS: Searches yielded 195 papers, of which, 79 were found to be relevant. Of those, 23 papers presented unique findings and 8 additional articles and technical papers were added to provide a comprehensive review. Overall, while there are potential concerns for all 3 decontamination methods, we found that vHP has the most evidence supporting its use in FFR decontamination consistent with CDC recommendation. CONCLUSIONS: Future research is recommended to evaluate biological inactivation and real world fit failures after FFR reuse.

Acute Necrotizing Encephalopathy: 2 Case Reports on RANBP2 Mutation.

Infection-induced acute encephalopathy 3 (IIAE3) is an autosomal dominant disease resulting from a pathogenic variant in the RANBP2 gene. IIAE3 results in the susceptibility to the recurrence of acute necrotizing encephalopathy (ANE1) which presents as bilateral symmetric thalamic, midbrain and/or hindbrain lesions that typically develops within 1-4 days post-acute viral infection, commonly occurring before age 6.1-6 These case reports highlight a retrospective analysis of clinical data and radiographic studies on 2 ANE1 cases from our institution. The novel p.Leu450Phe variant of the RANBP2 gene was analyzed using in silico algorithms (PolyPhen-2, SIFT, Mutationtaster) which suggests the p.Leu450Phe variant is probably deleterious.7 An expansion of documented ANE1 case presentations and clinically significant RANBP2 gene mutations has the potential to improve long term outcomes if more informed therapeutic decision making can be achieved.

Reduced Kv3.1 Activity in Dentate Gyrus Parvalbumin Cells Induces Vulnerability to Depression.

BACKGROUND: Parvalbumin (PV)-expressing interneurons are important for cognitive and emotional behaviors. These neurons express high levels of p11, a protein associated with depression and action of antidepressants. METHODS: We characterized the behavioral response to subthreshold stress in mice with conditional deletion of p11 in PV cells. Using chemogenetics, viral-mediated gene delivery, and a specific ion channel agonist, we studied the role of dentate gyrus PV cells in regulating anxiety-like behavior and resilience to stress. We used electrophysiology, imaging, and biochemical studies in mice and cells to elucidate the function and mechanism of p11 in dentate gyrus PV cells. RESULTS: p11 regulates the subcellular localization and cellular level of the potassium channel Kv3.1 in cells. Deletion of p11 from PV cells resulted in reduced hippocampal level of Kv3.1, attenuated capacity of high-frequency firing in dentate gyrus PV cells, and altered short-term plasticity at synapses on granule cells, as well as anxiety-like behavior and a pattern separation deficit. Chemogenetic inhibition or deletion of p11 in these cells induced vulnerability to depressive behavior, whereas upregulation of Kv3.1 in dentate gyrus PV cells or acute activation of Kv3.1 using a specific agonist induced resilience to depression. CONCLUSIONS: The activity of dentate gyrus PV cells plays a major role in the behavioral response to novelty and stress. Activation of the Kv3.1 channel in dentate gyrus PV cells may represent a target for the development of cell-type specific, fast-acting antidepressants.

Brain Permeable Tafamidis Amide Analogs for Stabilizing TTR and Reducing APP Cleavage.

Tafamidis, 1, a potent transthyretin kinetic stabilizer, weakly inhibits the γ-secretase enzyme in vitro. We have synthesized four amide derivatives of 1. These compounds reduce production of the Aß peptide in N2a695 cells but do not inhibit the γ-secretase enzyme in cell-free assays. By performing fluorescence correlation spectroscopy, we have shown that TTR inhibits Aß oligomerization and that addition of tafamidis or its amide derivative does not affect TTR's ability to inhibit Aß oligomerization. The piperazine amide derivative of tafamidis (1a) efficiently penetrates and accumulates in mouse brain and undergoes proteolysis under physiological conditions in mice to produce tafamidis.

A Pentacyclic Triterpene from Ligustrum lucidum Targets γ-Secretase.

Amyloid-beta peptides generated by ß-secretase- and γ-secretase-mediated successive cleavage of amyloid precursor protein are believed to play a causative role in Alzheimer's disease. Thus, reducing amyloid-beta generation by modulating γ-secretase remains a promising approach for Alzheimer's disease therapeutic development. Here, we screened fruit extracts of Ligustrum lucidum Ait. (Oleaceae) and identified active fractions that increase the C-terminal fragment of amyloid precursor protein and reduce amyloid-beta production in a neuronal cell line. These fractions contain a mixture of two isomeric pentacyclic triterpene natural products, 3-O-cis- or 3-O-trans-p-coumaroyl maslinic acid (OCMA), in different ratios. We further demonstrated that trans-OCMA specifically inhibits γ-secretase and decreases amyloid-beta levels without influencing cleavage of Notch. By using photoactivatable probes targeting the subsites residing in the γ-secretase active site, we demonstrated that trans-OCMA selectively affects the S1 subsite of the active site in this protease. Treatment of Alzheimer's disease transgenic model mice with trans-OCMA or an analogous carbamate derivative of a related pentacyclic triterpene natural product, oleanolic acid, rescued the impairment of synaptic plasticity. This work indicates that the naturally occurring compound trans-OCMA and its analogues could become a promising class of small molecules for Alzheimer's disease treatment.

Development of Kinase Inactive PD173955 Analogues for Reducing Production of Aß Peptides.

Compound 3a, DV2-103, is a kinase inactive analogue of a potent Abl1/Src kinase inhibitor, PD173955, 2. Both compounds, 2 and 3a, are known to reduce production of beta amyloid (Aß) peptide in cells and animal models. We have now prepared and evaluated a series of PD-173955 analogues, several of which reduced Aß production potently. This occurs in cells expressing human full-length amyloid precursor protein (APP) and not in cells expressing APP ß-C terminal fragment (APP-C99), suggesting that the kinase inactive analogues strongly affect ß-secretase (BACE1) cleavage of APP, similarly to Gleevec. A combination of the kinase inactive analogues of PD173955 with a BACE1 inhibitor (BACEi), namely, BACE IV, strongly reduced Aß levels in cells, as noted previously with Gleevec and analogues. Several potent compounds also penetrated and accumulated in mouse brain in high nanomolar to low micromolar concentration.

Development of Gleevec Analogues for Reducing Production of ß-Amyloid Peptides through Shifting ß-Cleavage of Amyloid Precursor Proteins.

Imatinib mesylate, 1a, inhibits production of ß-amyloid (Aß) peptides both in cells and in animal models. It reduces both the ß-secretase and γ-secretase cleavages of the amyloid precursor protein (APP) and mediates a synergistic effect, when combined with a ß-secretase inhibitor, BACE IV. Toward developing more potent brain-permeable leads, we have synthesized and evaluated over 75 1a-analogues. Several compounds, including 2a-b and 3a-c, inhibited production of Aß peptides with improved activity in cells. These compounds affected ß-secretase cleavage of APP similarly to 1a. Compound 2a significantly reduced production of the Aß42 peptide, when administered (100 mg/kg, twice daily by oral gavage) to 5 months old female mice for 5 days. A combination of compound 2a with BACE IV also reduced Aß levels in cells, more than the additive effect of the two compounds. These results open a new avenue for developing treatments for Alzheimer's disease using 1a-analogues.

Disruption of Golgi processing by 2-phenyl benzimidazole analogs blocks cell proliferation and slows tumor growth.

PURPOSE: Cancer chemotherapy continues to be challenged by the emergence of resistant tumors, and one organelle entwined in the development of drug resistance is the Golgi apparatus. Recently, we discovered a group of 2-(substituted phenyl)-benzimidazole (2-PB) compounds that displace resident Golgi proteins from the juxtanuclear region resulting in their degradation. These compounds are also potent anti-proliferative agents, which together with their action on the Golgi made a compelling case for testing them against cancer. METHODS: The anti-tumor activity of a group of 2-PB compounds was examined both in vitro and in vivo. The role of the Golgi in the anti-proliferative effect was assessed by comparing the proliferation of individual cell lines with the distribution and total cellular expression of selected resident Golgi proteins. RESULTS: The anti-proliferative activity of 2-PB compounds is partially reversible (time- and concentration-dependent), non-cell-cycle-specific, and translates to tumor growth inhibition in vivo. While 2-PB compounds displace resident Golgi proteins from the juxtanuclear region in all cells, those that are resistant to the anti-proliferative effects differ from sensitive cells in that they have the capacity to protect these Golgi proteins from degradation. CONCLUSIONS: These results illustrate the utility of targeting the Golgi for cancer drug development. They also reveal a cellular strategy for resisting 2-PB drug effects through protection of displaced Golgi proteins from degradation thus allowing their continued function.

2-phenylimidazopyridines, a new series of Golgi compounds with potent antiviral activity.

Drugs targeted to viral proteins are highly vulnerable to the development of resistant strains. We previously characterized a group of 2-phenylbenzimidazole compounds for their activity against allergy and asthma and more recently established the Golgi as their probable site of action. Herein we describe their activity against the propagation of several virus types through an action on the host cell. The most potent derivatives are the novel 2-phenylimidazopyridines, the lead compound of which is highly effective for blocking the spread of topical herpes infection in an animal model. These agents may provide an alternative antiviral approach, particularly for treating resistant strains.

Chuvash-type polycythemia in pregnancy managed by repeated venisections and heparin therapy: a case report.

BACKGROUND: Chuvash-type polycythemia is a rare blood disease associated with an increased tendency toward thrombosis and its resulting problems, which at times can be life threatening. The main goal of treatment is to prevent thrombosis and minimize the complications of therapy. CASE: A 20-year-old, Asian woman with her first pregnancy was admitted to the hospital at 16 weeks' gestation. Her initial blood work showed a hemoglobin level of 19 g/dL, hematocrit of 55% and erythropoietin level of 21.9 IU/L (laboratory reference range, 5-25). The results of a molecular analysis of the blood specimen confirmed the diagnosis of Chuvash-type polycythemia due to von Hippel-Lindau gene mutation. Weekly venisection until delivery was planned. Subsequently, the hemoglobin dropped to 15 g/dL and hematocrit to 44.6%. A 30-week scan demonstrated static growth below the third centile and oligohydramnios but normal Doppler findings. Prophylactic low-molecular-weight heparin was started. The next growth scan, at 32 weeks, showed an improvement in abdominal circumference. Three days later, fetal heart monitoring showed an abnormal pattern requiring an emergency cesarean section. CONCLUSION: Early institution of heparin is beneficial in the management of Chuvash-type polycythemia in pregnancy as the condition is thrombogenic.

Substituted 2-phenyl-benzimidazole derivatives: novel compounds that suppress key markers of allergy.

The pharmacotherapy of allergy and asthma has traditionally focused on the effecter molecules of the allergic cascade, while neglecting targets that play an early role in their development. Reasoning that IgE is central to the expansion of atopic diseases, we identified and extended a novel family of 2-(substituted phenyl)-benzimidazole inhibitors of IgE response. Pharmacological activity depends on an intact phenylbenzimidazole-bis-amide backbone, and is optimized by the presence of lipophilic terminal groups composed of either bis cycloalkyl or combinations of aliphatic and halogen-substituted aromatic groups. These compounds also inhibit IL-4 and IL-5 responses in T cells and CD23 expression on B cells, with potencies that parallel their inhibition of IgE. The broad profile of these compounds thus underscores their potential for treating the multifarious pathology of asthma.

Novel 2-(substituted phenyl)benzimidazole derivatives with potent activity against IgE, cytokines, and CD23 for the treatment of allergy and asthma.

The effectiveness of the injectable anti-IgE antibody omalizumab has validated IgE as an important target for allergic diseases, thus spawning the development of small-molecule IgE inhibitors. Herein, a brief SAR is described for novel phenylbenzimidazole compounds that potently suppress IgE responses. In addition to IgE, these agents inhibit other targets critical for allergic response. The profile of orally active AVP-13358, the lead compound of this series currently in clinical trials, is described.

A highly selective and specific PET tracer for imaging of tau pathologies.

Senile plaques and neurofibrillary tangles are prominent neuropathological hallmarks in Alzheimer's disease and are considered to be targets for therapeutic intervention as well as biomarkers for diagnostic in vivo imaging agents. While there are a number of amyloid-ß positron emission tomography (PET) tracers currently in different stages of clinical development and commercialization, there have been very few reports on imaging agents selectively targeting tau aggregates. In search of [18F]-PET tracers that possess great binding affinity and selectivity toward tau tangles, we tested more than 900 compounds utilizing a unique screening process. A competitive autoradiography assay was set up to test compounds for binding to native tau tangles and amyloid-ß plaques on human brain tissue sections. In our in vitro assays, the 18F labeled compound [18F]-T808 displayed a high level of binding affinity and good selectivity for tau aggregates over amyloid-ß plaques. [18F]-T808 showed rapid uptake and washout in rodent brains. Our in vitro and preclinical in vivo studies suggest that [18F]-T808 possesses suitable properties and characteristics to be a specific and selective PET probe for imaging of paired helical filament tau in human brains.