Alan P. Kozikowski

Bio: Alan P. Kozikowski is an academic researcher from University of Illinois at Chicago. The author has contributed to research in topics: Nicotinic agonist & Histone deacetylase. The author has an hindex of 55, co-authored 198 publications receiving 9996 citations. Previous affiliations of Alan P. Kozikowski include University of Chicago & University of Illinois at Urbana–Champaign.

Rational design and simple chemistry yield a superior, neuroprotective HDAC6 inhibitor, tubastatin A.

Abstract: Structure-based drug design combined with homology modeling techniques were used to develop potent inhibitors of HDAC6 that display superior selectivity for the HDAC6 isozyme compared to other inhibitors. These inhibitors can be assembled in a few synthetic steps, and thus are readily scaled up for in vivo studies. An optimized compound from this series, designated Tubastatin A, was tested in primary cortical neuron cultures in which it was found to induce elevated levels of acetylated α-tubulin, but not histone, consistent with its HDAC6 selectivity. Tubastatin A also conferred dose-dependent protection in primary cortical neuron cultures against glutathione depletion-induced oxidative stress. Importantly, when given alone at all concentrations tested, this hydroxamate-containing HDAC6-selective compound displayed no neuronal toxicity, thus, forecasting the potential application of this agent and its analogues to neurodegenerative conditions.

HDAC6 inhibitors reverse axonal loss in a mouse model of mutant HSPB1–induced Charcot-Marie-Tooth disease

Abstract: Charcot-Marie-Tooth disease (CMT) is the most common inherited disorder of the peripheral nervous system. Mutations in the 27-kDa small heat-shock protein gene (HSPB1) cause axonal CMT or distal hereditary motor neuropathy (distal HMN). We developed and characterized transgenic mice expressing two different HSPB1 mutations (S135F and P182L) in neurons only. These mice showed all features of CMT or distal HMN dependent on the mutation. Expression of mutant HSPB1 decreased acetylated α-tubulin abundance and induced severe axonal transport deficits. An increase of α-tubulin acetylation induced by pharmacological inhibition of histone deacetylase 6 (HDAC6) corrected the axonal transport defects caused by HSPB1 mutations and rescued the CMT phenotype of symptomatic mutant HSPB1 mice. Our findings demonstrate the pathogenic role of α-tubulin deacetylation in mutant HSPB1-induced neuropathies and offer perspectives for using HDAC6 inhibitors as a therapeutic strategy for hereditary axonopathies.

HDAC6 is a target for protection and regeneration following injury in the nervous system

Abstract: Central nervous system (CNS) trauma can result in tissue disruption, neuronal and axonal degeneration, and neurological dysfunction. The limited spontaneous CNS repair in adulthood and aging is often insufficient to overcome disability. Several investigations have demonstrated that targeting HDAC activity can protect neurons and glia and improve outcomes in CNS injury and disease models. However, the enthusiasm for pan-HDAC inhibition in treating neurological conditions is tempered by their toxicity toward a host of CNS cell types -a biological extension of their anticancer properties. Identification of the HDAC isoform, or isoforms, that specifically mediate the beneficial effects of pan-HDAC inhibition could overcome this concern. Here, we show that pan-HDAC inhibition not only promotes neuronal protection against oxidative stress, a common mediator of injury in many neurological conditions, but also promotes neurite growth on myelin-associated glycoprotein and chondroitin sulfate proteoglycan substrates. Real-time PCR revealed a robust and selective increase in HDAC6 expression due to injury in neurons. Accordingly, we have used pharmacological and genetic approaches to demonstrate that inhibition of HDAC6 can promote survival and regeneration of neurons. Consistent with a cytoplasmic localization, the biological effects of HDAC6 inhibition appear transcription-independent. Notably, we find that selective inhibition of HDAC6 avoids cell death associated with pan-HDAC inhibition. Together, these findings define HDAC6 as a potential nontoxic therapeutic target for ameliorating CNS injury characterized by oxidative stress-induced neurodegeneration and insufficient axonal regeneration.

A series of halogenated heterodimeric inhibitors of prostate specific membrane antigen (PSMA) as radiolabeled probes for targeting prostate cancer.

Abstract: Prostate specific membrane antigen (PSMA) is a validated molecular marker for prostate cancer. A series of glutamate-urea (Glu-urea-X) heterodimeric inhibitors of PSMA were designed and synthesized where X = epsilon-N-(o-I, m-I, p-I, p-Br, o-Cl, m-Cl, p-Cl, p-F, H)-benzyl-Lys and epsilon-(p-I, p-Br, p-Cl, p-F, H)-phenylureido-Lys. The affinities for PSMA were determined by screening in a competitive binding assay. PSMA binding of the benzyllysine series was significantly affected by the nature of the halogen substituent (IC(50) values, Cl < I = Br << F = H) and the ring position of the halogen atom (IC(50) values, p-I < o-I << m-I). The halogen atom had little affect on the binding affinity in the para substituted phenylureido-Lys series. Two lead iodine compounds were radiolabeled with (123)I and (131)I and demonstrated specific PSMA binding on human prostate cancer cells, warranting evaluation as radioligands for the detection, staging, and monitoring of prostate cancer.

Radiolabeled Small-Molecule Ligands for Prostate-Specific Membrane Antigen: In vivo Imaging in Experimental Models of Prostate Cancer

Abstract: Purpose: Prostate-specific membrane antigen (PSMA) is a cell surface protein that is overexpressed in prostate cancer, including hormone-refractory and metastatic disease. Our goal in this study was to develop a series of PSMA-based imaging agents for clinical use. Experimental Design: We have synthesized and evaluated the in vivo biodistribution of two radiolabeled urea derivatives that have high affinity for PSMA in severe combined immunodeficient mice harboring MCF-7 (breast, PSMA-negative), PC-3 (prostate, PSMA-negative), and LNCaP (prostate, PSMA-positive) xenografts. Radiopharmaceutical binding selectivity and tumor uptake were also evaluated in vivo using dedicated small animal positron emission tomography, single photon emission computed tomography, and gamma scintigraphic imaging devices. N -[ N -[( S )-1,3-dicarboxypropyl]carbamoyl]- S -[ 11 C]methyl-l-cysteine ([ 11 C]DCMC K i , 3.1 nmol/L) and N -[ N -[( S )-1,3-dicarboxypropyl]carbamoyl]- S -3-[ 125 I]iodo-l-tyrosine ([ 125 C]DCIT K i , 1.5 nmol/L) were synthesized using [ 11 C]CH 3 I and with [ 125 I]NaI/Iodogen, respectively. Results: At 30 minutes postinjection, [ 11 C]DCMC and [ 125 I]DCIT showed tumor/muscle ratios of 10.8 and 4.7, respectively, with clear delineation of LNCaP-derived tumors on imaging. MCF-7- and PC-3-derived tumors showed significantly less uptake of [ 11 C]DCMC or [ 125 I]DCIT. Conclusion: These results show the feasibility of imaging PSMA-positive prostate cancer using low molecular weight agents.

The Halogen Bond

Abstract: The halogen bond occurs when there is evidence of a net attractive interaction between an electrophilic region associated with a halogen atom in a molecular entity and a nucleophilic region in another, or the same, molecular entity. In this fairly extensive review, after a brief history of the interaction, we will provide the reader with a snapshot of where the research on the halogen bond is now, and, perhaps, where it is going. The specific advantages brought up by a design based on the use of the halogen bond will be demonstrated in quite different fields spanning from material sciences to biomolecular recognition and drug design.

The Sonogashira Reaction: A Booming Methodology in Synthetic Organic Chemistry†

Abstract: 3.7. Palladium Nanoparticles as Catalysts 888 3.8. Other Transition-Metal Complexes 888 3.9. Transition-Metal-Free Reactions 889 4. Applications 889 4.1. Alkynylation of Arenes 889 4.2. Alkynylation of Heterocycles 891 4.3. Synthesis of Enynes and Enediynes 894 4.4. Synthesis of Ynones 896 4.5. Synthesis of Carbocyclic Systems 897 4.6. Synthesis of Heterocyclic Systems 898 4.7. Synthesis of Natural Products 903 4.8. Synthesis of Electronic and Electrooptical Molecules 906

The many roles of histone deacetylases in development and physiology: Implications for disease and therapy

Abstract: Histone deacetylases (HDACs) are part of a vast family of enzymes that have crucial roles in numerous biological processes, largely through their repressive influence on transcription. The expression of many HDAC isoforms in eukaryotic cells raises questions about their possible specificity or redundancy, and whether they control global or specific programmes of gene expression. Recent analyses of HDAC knockout mice have revealed highly specific functions of individual HDACs in development and disease. Mutant mice lacking individual HDACs are a powerful tool for defining the functions of HDACs in vivo and the molecular targets of HDAC inhibitors in disease.

Amyloid Oligomers Exacerbate Tau Pathology in a Mouse Model of Tauopathy

Abstract: Background: We aimed to investigate the influence of oligomeric forms of β-amyloid (Aβ) and the influence of the duration of exposure on the development of tau ph

Best Practices for QSAR Model Development, Validation, and Exploitation.

Abstract: After nearly five decades "in the making", QSAR modeling has established itself as one of the major computational molecular modeling methodologies. As any mature research discipline, QSAR modeling can be characterized by a collection of well defined protocols and procedures that enable the expert application of the method for exploring and exploiting ever growing collections of biologically active chemical compounds. This review examines most critical QSAR modeling routines that we regard as best practices in the field. We discuss these procedures in the context of integrative predictive QSAR modeling workflow that is focused on achieving models of the highest statistical rigor and external predictive power. Specific elements of the workflow consist of data preparation including chemical structure (and when possible, associated biological data) curation, outlier detection, dataset balancing, and model validation. We especially emphasize procedures used to validate models, both internally and externally, as well as the need to define model applicability domains that should be used when models are employed for the prediction of external compounds or compound libraries. Finally, we present several examples of successful applications of QSAR models for virtual screening to identify experimentally confirmed hits.