Understanding the Impact of the COVID-19 Pandemic on the Perception and Use of Urban Green Spaces in Korea.

Faced with the prospect that the impact of the COVID-19 pandemic and climate change will be far-reaching and long-term, the international community is showing interest in urban green space (UGS) and urban green infrastructure utilization as a solution. In this study, we investigated how citizens' perceptions and use of UGS have changed during COVID-19. We also collected their ideas on how UGS can raise its usability. As a result, more people became to realize the importance of UGS. In particular, the urban environmental purification function from UGS was recognized as giving great benefits to respondents. On the other hand, the patterns of UGS use were mixed with decreasing UGS use to maintain social distancing or increasing UGS use to maintain health or substitute other restricted facilities. More than half of respondents had their UGS visit patterns impacted by COVID-19. In particular, the increase rate of UGS use was rather high in the group that seldom used UGS before COVID-19. In addition, they increased the use of UGS to replace other limited facilities, and thus tended to demand an increase in rest facilities. Based on these results, this paper suggested securing social support and sustainability for the policy by reflecting users' demand in landscape planning related to the increase of UGS in the city. This study can contribute to improving the resilience of UGS and the sustainability of urban space planning.

Discovery of Selective SIRT2 Inhibitors as Therapeutic Agents in B-Cell Lymphoma and Other Malignancies.

Genetic ablation as well as pharmacological inhibition of sirtuin 2 (SIRT2), an NAD+-dependent protein deacylase, have therapeutic effects in various cancers and neurodegenerative diseases. Previously, we described the discovery of a dual SIRT1/SIRT2 inhibitor called cambinol (IC50 56 and 59 µM, respectively), which showed cytotoxic activity against cancer cells in vitro and a marked anti-proliferative effect in a Burkitt lymphoma mouse xenograft model. A number of recent studies have shown a protective effect of SIRT1 and SIRT3 in neurodegenerative and metabolic diseases as well as in certain cancers prompting us to initiate a medicinal chemistry effort to develop cambinol-based SIRT2-specific inhibitors devoid of SIRT1 or SIRT3 modulating activity. Here we describe potent cambinol-based SIRT2 inhibitors, several of which show potency of ~600 nM with >300 to >800-fold selectivity over SIRT1 and 3, respectively. In vitro, these inhibitors are found to be toxic to lymphoma and epithelial cancer cell lines. In particular, compounds 55 (IC50 SIRT2 0.25 µM and <25% inhibition at 50 µM against SIRT1 and SIRT3) and 56 (IC50 SIRT2 0.78 µM and <25% inhibition at 50 µM against SIRT1 and SIRT3) showed apoptotic as well as strong anti-proliferative properties against B-cell lymphoma cells.

Fate plasticity and reprogramming in genetically distinct populations of Danio leucophores.

Understanding genetic and cellular bases of adult form remains a fundamental goal at the intersection of developmental and evolutionary biology. The skin pigment cells of vertebrates, derived from embryonic neural crest, are a useful system for elucidating mechanisms of fate specification, pattern formation, and how particular phenotypes impact organismal behavior and ecology. In a survey of Danio fishes, including the zebrafish Danio rerio, we identified two populations of white pigment cells-leucophores-one of which arises by transdifferentiation of adult melanophores and another of which develops from a yellow-orange xanthophore or xanthophore-like progenitor. Single-cell transcriptomic, mutational, chemical, and ultrastructural analyses of zebrafish leucophores revealed cell-type-specific chemical compositions, organelle configurations, and genetic requirements. At the organismal level, we identified distinct physiological responses of leucophores during environmental background matching, and we showed that leucophore complement influences behavior. Together, our studies reveal independently arisen pigment cell types and mechanisms of fate acquisition in zebrafish and illustrate how concerted analyses across hierarchical levels can provide insights into phenotypes and their evolution.

Phenotypic Optimization of Urea-Thiophene Carboxamides To Yield Potent, Well Tolerated, and Orally Active Protective Agents against Aminoglycoside-Induced Hearing Loss.

Hearing loss is a major public health concern with no pharmaceutical intervention for hearing protection or restoration. Using zebrafish neuromast hair cells, a robust model for mammalian auditory and vestibular hair cells, we identified a urea-thiophene carboxamide, 1 (ORC-001), as protective against aminoglycoside antibiotic (AGA)-induced hair cell death. The 50% protection (HC50) concentration conferred by 1 is 3.2 µM with protection against 200 µM neomycin approaching 100%. Compound 1 was sufficiently safe and drug-like to validate otoprotection in an in vivo rat hearing loss model. We explored the structure-activity relationship (SAR) of this compound series to improve otoprotective potency, improve pharmacokinetic properties and eliminate off-target activity. We present the optimization of 1 to yield 90 (ORC-13661). Compound 90 protects mechanosensory hair cells with HC50 of 120 nM and demonstrates 100% protection in the zebrafish assay and superior physiochemical, pharmacokinetic, and toxicologic properties, as well as complete in vivo protection in rats.

Deoxygenation of Unhindered Alcohols via Reductive Dealkylation of Derived Phosphate Esters.

Primary alcohols can be deoxygenated cleanly and in yields of 60-95% by reduction of derived diphenyl phosphate esters with lithium triethylborohydride in tetrahydrofuran at room temperature. Selective deoxygenation of a primary alcohol in the presence of a secondary alcohol was demonstrated. The two-step process can be performed in one pot, making it simple and convenient.

Amino acid derived quinazolines as Rock/PKA inhibitors.

SAR and lead optimization studies for Rock inhibitors based on amino acid-derived quinazolines are described. Studies demonstrated that these amino acid derived quinazolinones were mainly pan-Rock (I & II) inhibitors. While selectivity against other kinases could be achieved, selectivity for most of these compounds against PKA was not achieved. This is distinct from Rock inhibitors based on non-amino acid derived quinazolinones, where high selectivity against PKA could be obtained.(22) The inhibitors presented here in some cases possessed sub-nanomolar inhibition of Rock, nanomolar potency in ppMLC cell based assays, low to fair cytochrome P-450 inhibition, and good human microsomal stability.

Discovery and optimization of indole and 7-azaindoles as Rho kinase (ROCK) inhibitors (part-II).

Therapeutic interventions with Rho kinase (ROCK) inhibitors may effectively treat several disorders such as hypertension, stroke, cancer, and glaucoma. Herein we disclose the optimization and biological evaluation of potent novel ROCK inhibitors based on substituted indole and 7-azaindole core scaffolds. Substitutions on the indole C3 position and on the indole NH and/or amide NH positions all yielded potent and selective ROCK inhibitors (25, 42, and 50). Improvement of aqueous solubility and tailoring of in vitro and in vivo DMPK properties could be achieved through these substitutions.

Discovery and optimization of indoles and 7-azaindoles as Rho kinase (ROCK) inhibitors (part-I).

Rho kinase (ROCK) inhibitors are potential therapeutic agents to treat disorders such as hypertension, multiple sclerosis, cancers, and glaucoma. Here, we disclose the synthesis, optimization, biological evaluation of potent indole and 7-azaindole based ROCK inhibitors that have high potency on ROCK (IC(50)=1 nM) with 740-fold selectivity over PKA (47). Moreover, 47 showed very good DMPK properties making it a good candidate for further development. Finally, docking studies with a homology model of ROCK-II were performed to rationalize the binding mode of these compounds and showed the compounds bound in both orientations to take advantage to H-bonds with Lys-121 of ROCK-II.

Identification of small-molecule inhibitors of the colorectal cancer oncogene Krüppel-like factor 5 expression by ultrahigh-throughput screening.

The transcription factor Krüppel-like factor 5 (KLF5) is primarily expressed in the proliferative zone of the mammalian intestinal epithelium, where it regulates cell proliferation. Studies showed that inhibition of KLF5 expression reduces proliferation rates in human colorectal cancer cells and intestinal tumor formation in mice. To identify chemical probes that decrease levels of KLF5, we used cell-based ultrahigh-throughput screening (uHTS) to test compounds in the public domain of NIH, the Molecular Libraries Probe Production Centers Network library. The primary screen involved luciferase assays in the DLD-1/pGL4.18hKLF5p cell line, which stably expressed a luciferase reporter driven by the human KLF5 promoter. A cytotoxicity counterscreen was done in the rat intestinal epithelial cell line, IEC-6. We identified 97 KLF5-selective compounds with EC(50) < 10 µmol/L for KLF5 inhibition and EC(50) > 10 µmol/L for IEC-6 cytotoxicity. The two most potent compounds, CIDs (PubChem Compound IDs) 439501 and 5951923, were further characterized on the basis of computational, Western blot, and cell viability analyses. Both of these compounds, and two newly synthesized structural analogs of CID 5951923, significantly reduced endogenous KLF5 protein levels and decreased viability of several colorectal cancer cell lines without any apparent impact on IEC-6 cells. Finally, when tested in the NCI-60 panel of human cancer cell lines, compound CID 5951923 was selectively active against colon cancer cells. Our results show the feasibility of uHTS in identifying novel compounds that inhibit colorectal cancer cell proliferation by targeting KLF5.

Synthesis and biological evaluation of 4-quinazolinones as Rho kinase inhibitors.

Rho kinase (ROCK) is an attractive therapeutic target for various diseases including glaucoma, hypertension, and spinal cord injury. Herein, we report the development of a series of ROCK-II inhibitors based on 4-quinazolinone and quinazoline scaffolds. SAR studies at three positions of the quinazoline core led to the identification of analogs with high potency against ROCK-II and good selectivity over protein kinase A (PKA).

The development of benzimidazoles as selective rho kinase inhibitors.

Rho Kinase (ROCK) is a serine/threonine kinase whose inhibition could prove beneficial in numerous therapeutic areas. We have developed a promising class of ATP-competitive inhibitors based upon a benzimidazole scaffold, which show excellent potency toward ROCK (IC(50)<10nM). This report details the optimization of selectivity for ROCK over other related kinases such as Protein kinase A (PKA).

Phosphonic acid analogs of GABA through reductive dealkylation of phosphonic diesters with lithium trialkylborohydrides.

Lithium trialkylborohydrides were found to effect rapid monodealkylation of phosphonic diesters, and this reaction was applied to the synthesis of alkylphosphonic acid 2-aminoethyl esters [H(2)N(CH(2))(2)OP(OH)R, 4], a little-explored class of analogs of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). Compound 4a (R=Me) proved to be a potent antagonist at human rho1 GABA(C) receptors (expressed in Xenopus laevis oocytes), with an IC(50) of 11.1 microM, but is inactive at alpha(1)beta(2)gamma(2) GABA(A) receptors.

Activation of membrane receptors by a neurotransmitter conjugate designed for surface attachment.

The derivatization of surfaces with bioactive molecules is a research area of growing importance for cell and tissue engineering. Tetherable molecules used in such applications must contain an anchoring moiety as well as the biofunctional group, typically along with a spacer to prevent steric clashes between the target molecule and the tethering surface. Post-synaptic membrane receptors at chemical synapses in neural tissue mediate signaling to the post-synaptic neuron and are activated by the binding of diffusible neurotransmitter molecules released by the pre-synaptic neuron. However, little attention has been directed at developing neurotransmitter analogs that might retain functionality when tethered to a surface that could be interfaced with post-synaptic receptor proteins. Muscimol (5-aminomethyl-3-hydroxyisoxazole), an analog of GABA (gamma-aminobutryic acid), is a known potent agonist of GABA(A) and GABA(C) post-synaptic receptors found in retina and other central nervous system tissue. The present paper reports experiments testing the electrophysiological activity of "muscimol-biotin" on cloned GABA receptors expressed in Xenopus oocytes. This compound, which is potentially suitable for tethering at avidin-coated surfaces, consists of muscimol conjugated through an N-acyl linkage to a 6-aminohexanoyl chain that is distally terminated by biotin. We find that muscimol-biotin, as well as a structurally similar compound (muscimol-BODIPY) containing a bulky fluorophore at the distal end of the aminohexanoyl chain, exhibits substantial agonist activity at GABA(A) and GABA(C) receptors. Muscimol-biotin and other similarly biotinylated neurotransmitter analogs, in combination with surface functionalization using avidin-biotin technology, may be useful in applications involving the controlled activation of neuronal post-synaptic receptors by surface-attached molecules.

Neurotransmitter analog tethered to a silicon platform for neuro-BioMEMS applications.

The design of chemically well-defined, machinable surfaces containing neuroactive molecules offers potential for fundamental neuroscience and clinical neural engineering applications. Here we report the assembly and characterization of silicon platforms containing a tethered form of muscimol. Muscimol, an analog of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA), is a potent agonist at postsynaptic GABA(A) and GABA(C) receptors. Surfaces were assembled using covalent avidin conjugation to silanized silicon followed by high-affinity avidin-biotin binding of a biotinylated derivative of muscimol (muscimol-biotin). Contact angle measurements, ellipsometry, and X-ray photoelectron spectroscopy (XPS) were conducted to characterize the wettability, thickness, and chemical composition of progressively deposited surface layers. The data demonstrate successful incorporation of a neurotransmitter analog as part of a layered, silicon-based structure possessing robust and specific biomolecular composition. These findings represent a step toward the design of platforms for applications involving control and modulation of neural signaling.