An algorithm for defining the onset and cessation of the flexion-relaxation phenomenon in the low back musculature

The flexion-relaxation phenomenon (FRP) in the low back provides insights into the interplay between the active and passive tissues. Establishing a reliable algorithm for defining the lumbar angle at which the muscles deactivate and reactivate was the focus of the current paper. First, the EMG data were processed using six different smoothing techniques (no smoothing, moving average, moving standard deviation, Butterworth low pass filter at 0.5 Hz, 5 Hz, and 50 Hz) herein called the processed EMG (pEMG). The FRP points were then defined using four thresholds (pEMG less than 3% MVC, pEMG less than 5% MVC, pEMG less than 2 times FRP pEMG, and pEMG less than 3 times FRP pEMG). Finally, a duration requirement was tested (no duration requirement, pEMG data must maintain threshold requirement for 50 data points). Each combination of smoothing, threshold, and duration were applied through a computer program to each muscle for all trials and established an EMG-off and EMG-on angle for each muscle. These estimates were compared to the gold standard of expert-identified EMG-off and EMG-on angles and the root mean square error (RMSE) between this gold standard and the predictions of the algorithms served as the dependent variable. The results showed that the most important factor to produce low values of RMSE is to utilize a Butterworth low pass filter of 5 Hz or less and, if this is employed, there is no value to a duration requirement. The results also suggest that using the "3 times FRP pEMG" threshold technique may provide further improvements in these predictions.     

Synthesis and biological evaluation of 3-acyl-2-phenylamino-1,4-dihydroquinolin-4(1H)-one derivatives as potential MERS-CoV inhibitors

3-Acyl-2-phenylamino-1,4-dihydroquinolin-4(1H)-one derivatives were synthesized and evaluated to show high anti-MERS-CoV inhibitory activities. Among them, 6,8-difluoro-3-isobutyryl-2-((2,3,4-trifluorophenyl)amino)quinolin-4(1H)-one (6u) exhibits high inhibitory effect (IC₅₀ = 86 nM) and low toxicity (CC₅₀ > 25 μM). Moreover, it shows good metabolic stability, low hERG binding affinity, no cytotoxicity, and good in vivo PK properties.     

Retinol binding protein-albumin domain III fusion protein deactivates hepatic stellate cells

Liver fibrosis is characterized by accumulation of extracellular matrix, and activated hepatic stellate cells (HSCs) are the primary source of the fibrotic neomatrix and considered as therapeutic target cells. We previously showed that albumin in pancreatic stellate cells (PSCs), the key cell type for pancreatic fibrogenesis, is directly involved in the formation of vitamin A-containing lipid droplets, inhibiting PSC activation. In this study, we evaluated the anti-fibrotic activity of both albumin and retinol binding protein-albumin domain III fusion protein (R-III), designed for stellate cell-targeted delivery of albumin III, in rat primary HSCs and investigated the underlying mechanism. Forced expression of albumin or R-III in HSCs after passage 2 (activated HSCs) induced lipid droplet formation and deactivated HSCs, whereas point mutations in high-affinity fatty acid binding sites of albumin domain III abolished their activities. Exogenous R-III, but not albumin, was successfully internalized into and deactivated HSC-P2. When HSCs at day 3 after plating (pre-activated HSCs) were cultured in the presence of purified R-III, spontaneous activation of HSCs was inhibited even after passage 2, suggestive of a potential for preventive effect. Furthermore, treatment of HSCs-P2 with R-III led to a significant reduction in both cytoplasmic levels of all-trans retinoic acid and the subsequent retinoic acid signaling. Therefore, our data suggest that albumin deactivates HSCs with reduced retinoic acid levels and that R-III may have therapeutic and preventive potentials on liver fibrosis.     

Recombinant fusion protein of albumin-retinol binding protein inactivates stellate cells

Quiescent pancreatic- (PSCs) and hepatic- (HSCs) stellate cells store vitamin A (retinol) in lipid droplets via retinol binding protein (RBP) receptor and, when activated by profibrogenic stimuli, they transform into myofibroblast-like cells which play a key role in the fibrogenesis. Despite extensive investigations, there is, however, currently no appropriate therapy available for tissue fibrosis. We previously showed that the expression of albumin, composed of three homologous domains (I-III), inhibits stellate cell activation, which requires its high-affinity fatty acid-binding sites asymmetrically distributed in domain I and III. To attain stellate cell-specific uptake, albumin (domain I/III) was coupled to RBP; RBP-albumin(domain III) (R-III) and albumin(domain I)-RBP-albumin(III) (I-R-III). To assess the biological activity of fusion proteins, cultured PSCs were used. Like wild type albumin, expression of R-III or I-R-III in PSCs after passage 2 (activated PSCs) induced phenotypic reversal from activated to fat-storing cells. On the other hand, R-III and I-R-III, but not albumin, secreted from transfected 293 cells were successfully internalized into and inactivated PSCs. FPLC-purified R-III was found to be internalized into PSCs via caveolae-mediated endocytosis, and its efficient cellular uptake was also observed in HSCs and podocytes among several cell lines tested. Moreover, tissue distribution of intravenously injected R-III was closely similar to that of RBP. Therefore, our data suggest that albumin-RBP fusion protein comprises of stellate cell inactivation-inducing moiety and targeting moiety, which may lead to the development of effective anti-fibrotic drug.     

Effect of hemp fiber on UVB-induced epidermal cell proliferation and PCNA expression

Ultraviolet radiation commonly causes serious skin diseases, and skin cell death. The UVB-blocking effect of hemp fabric which known to be a powerful agent against UVB was evaluated using mouse auricle skin. Based on UVB irradiation and the use of different fabrics, four mouse groups were evaluated in this study: two experimental groups, Group 1 (UVB exposed hemp fabric-shield site, EHFS), Group 2 (UVB exposed polyester fabric-shield site, EPFS), and two control groups, Group 3 (UVB exposed non-fabric-shield site, ENFS), and Group 4 (UVB unexposed non-fabric-shield site, UNFS). Except for UNFS all samples were exposed to UVB for 28 h and showed clear histologic changes in epidermis and dermis. After 45 h chronic irradiation, epidermal thickness was doubled in EHFS, roughly tripled in EPFS, and more than quadrupled in ENFS over that of UNFS. Based on the thickness of the altered epidermis, the blocking effect of hemp fabric was 50% higher than that of polyester fabric. Additionally, immunohistochemical analysis revealed expression of proliferating cell nuclear antigen (PCNA) in ENFS and EPFS throughout the hyperplasia of keratinocytes and sebocytes. After 45 h irradiation, the sebocytes of sebaceous glands, observed in sectioned images, increased on average to 14 cells in ENFS, 9 cells in EPFS, and 7 cells in EHFS, as compared to 8 cells in UNFS. In contrast, the cell area of adipose tissue was decreased by half in EHFS, one-fourth in EPFS, and one-tenth in ENFS, and mostly replaced with fibroblasts and other supporting cells. These results suggest that UVB irradiation directly affects epidermal and dermal tissues, and induces abnormal proliferation of keratinocytes and hyperplasia of sebocytes consuming fats in adipose tissue. For skin health, hemp fabric is a better material for protecting the skin against UVB than polyester fabric.     

Selective α-glucosidase substrates and inhibitors containing short aromatic peptidyl moieties

We constructed a library of sugar-dipeptide conjugate to find out the best complementary against hydrophobic pocket of α-glucosidase. The best substrate showed 150-fold improved K_m value relative p-acetaminophenyl-α-d-glucopyranoside for α-glucosidase from Bacillus stearothermophillus. Using information from the complementary, we synthesized sp-WY and β-Glc-sp-WY, which selectivity inhibited the cognate enzyme.     

An approach for differentiating isozymes. Construction of libraries containing short aromatic peptides as part of a method to design selective inhibitors against lipases

Through synthesis and assays of peptidyl substrates, we could select substrates having peptidyl complementary against lipases. The best substrate showed 20-fold improved K(m) relative to non-peptidyl substrate. Using this information, we generated selective inhibitors. Lipase activities with peptidyl substrates were represented as fingerprints. Differences in fingerprints reflect different structures near active site of lipases, could be used for generating selective inhibitors.     

Design,synthesis, docking and biological evaluation of 4-phenyl-thiazole derivatives as autotaxin (ATX) inhibitors

The autotaxin-lysophophatidic acid (ATX-LPA) signaling pathway is involved in several human diseases such as cancer, autoimmune diseases, inflammatory diseases neurodegenerative diseases and fibrotic diseases. Herein, a series of 4-phenyl-thiazole based compounds was designed and synthesized. Compounds were evaluated for their ATX inhibitory activity using FS-3 and human plasma assays. In the FS-3 assay, compounds 20 and 21 significantly inhibited the ATX at low nanomolar level (IC₅₀ = 2.99 and 2.19 nM, respectively). Inhibitory activity of 21 was found to be slightly better than PF-8380 (IC₅₀ = 2.80 nM), which is one of the most potent ATX inhibitors reported till date. Furthermore, 21 displayed higher potency (IC₅₀ = 14.99 nM) than the first clinical ATX inhibitor, GLPG1690 (IC₅₀ = 242.00 nM) in the human plasma assay. Molecular docking studies were carried out to explore the binding pattern of newly synthesized compounds within active site of ATX. Docking studies suggested the putative binding mode of the novel compounds. Good ATX inhibitory activity of 21 was attributed to the hydrogen bonding interactions with Asn230, Trp275 and active site water molecules; electrostatic interaction with catalytic zinc ion and hydrophobic interactions with amino acids of the hydrophobic pocket.