G Protein-Coupled Estrogen Receptor-Mediated Anti-Inflammatory and Mucosal Healing Activity of a Trimethylpyridinol Analogue in Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is characterized by abnormal immune responses, including elevated proinflammatory cytokines, such as tumor necrosis factor-α (TNFα) and interleukin-6 (IL-6) in the gastrointestinal (GI) tract. This study presents the synthesis and anti-inflammatory evaluation of 2,4,5-trimethylpyridin-3-ol analogues, which exhibit dual inhibition of TNFα- and IL-6-induced inflammation. Analysis using in silico methods, including 3D shape-based target identification, modeling, and docking, identified G protein-coupled estrogen receptor 1 (GPER) as the molecular target for the most effective analogue, 6-26, which exhibits remarkable efficacy in ameliorating inflammation and restoring colonic mucosal integrity. This was further validated by surface plasmon resonance (SPR) assay results, which showed direct binding to GPER, and by the results showing that GPER knockdown abolished the inhibitory effects of 6-26 on TNFα and IL-6 actions. Notably, 6-26 displayed no cytotoxicity, unlike G1 and G15, a well-known GPER agonist and an antagonist, respectively, which induced necroptosis independently of GPER. These findings suggest that the GPER-selective compound 6-26 holds promise as a therapeutic candidate for IBD.

Curcuma phaeocaulis Inhibits NLRP3 Inflammasome in Macrophages and Ameliorates Nanoparticle-Induced Airway Inflammation in Mice.

The activation of NLRP3 results in the assembly of inflammasome that regulates caspase-1 activation and the subsequent secretion of bioactive interleukin (IL)-1ß. Excessive activation of the NLRP3 inflammasome is mechanistically linked to diverse pathophysiological conditions, including airway inflammation. Here, we discovered that Curcuma phaeocaulis can suppress caspase-1 activation and processing of pro-IL-1ß into mature cytokine in macrophages stimulated with NLRP3 inflammasome activators, such as SiO2 or TiO2 nanoparticles. Furthermore, in the bronchoalveolar lavage fluids of animals administered the nanoparticles, the in vitro effects of C. phaeocaulis translated into a decrease in IL-1ß levels and cell infiltration. Demethoxycurcumin (DMC) and curcumin were found to be responsible for the inflammasome inhibitory activity of C. phaeocaulis. Interestingly, in contrast to the previously reported higher antioxidant- and NFκB-inhibitory activities of curcumin, DMC exhibited approximately two-fold stronger potency than curcumin against nanoparticle induced activation of NLRP3 inflammasome. In the light of these results, both compounds seem to act independently of their antioxidant- and NFκB-inhibitory properties. Although how C. phaeocaulis inhibits nanoparticle-activated NLRP3 inflammasome remains to be elucidated, our results provide a basis for further research on C. phaeocaulis extract as an anti-inflammatory agent for the treatment of disorders associated with excessive activation of NLRP3 inflammasome.

Early-life body mass index and risks of breast, endometrial, and ovarian cancers: a dose-response meta-analysis of prospective studies.

BACKGROUND: The evidence for the associations between early-life adiposity and female cancer risks is mixed. Little is known about the exact shape of the relationships and whether the associations are independent of adult adiposity. METHODS: We conducted dose-response meta-analyses of prospective studies to summarise the relationships of early-life body mass index (BMI) with breast, endometrial, and ovarian cancer risks. Pubmed and Embase were searched through June 2020 to identify relevant studies. Using random-effects models, the summary relative risks (RRs) and 95% confidence intervals (CIs) were estimated per 5-kg/m2 increase in BMI at ages ≤ 25 years. A nonlinear dose-response meta-analysis was conducted using restricted cubic spline analysis. RESULTS: After screening 33,948 publications, 37 prospective studies were included in this analysis. The summary RRs associated with every 5-kg/m2 increase in early-life BMI were 0.84 (95% CI = 0.81-0.87) for breast, 1.40 (95% CI = 1.25-1.57) for endometrial, and 1.15 (95% CI = 1.07-1.23) for ovarian cancers. For breast cancer, the association remained statistically significant after adjustment for adult BMI (RR = 0.80, 95% CI = 0.73-0.87). For premenopausal breast, endometrial, and ovarian cancers, the dose-response curves suggested evidence of nonlinearity. CONCLUSIONS: With early-life adiposity, our data support an inverse association with breast cancer and positive associations with ovarian and endometrial cancer risks.

Demonstration of elementary functions via DNA algorithmic self-assembly.

Target-oriented cellular automata with computation are the primary challenge in the field of DNA algorithmic self-assembly in connection with specific rules. We investigate the feasibility of using the principle of cellular automata for mathematical subjects by using specific logic gates that can be implemented into DNA building blocks. Here, we connect the following five representative elementary functions: (i) enumeration of multiples of 2, 3, and 4 (demonstrated via R094, R062, and R190 in 3-input/1-output logic rules); (ii) the remainder of 0 and 1 (R132); (iii) powers of 2 (R129); (iv) ceiling function for n/2 and n/4 (R152 and R144); and (v) analogous pattern of annihilation (R184) to DNA algorithmic patterns formed by specific rules. After designing the abstract building blocks and simulating the generation of algorithmic lattices, we conducted an experiment as follows: designing of DNA tiles with specific sticky ends, construction of DNA lattices via a two-step annealing method, and verification of expected algorithmic patterns on a given DNA lattice using an atomic force microscope (AFM). We observed representative patterns, such as horizontal and diagonal stripes and embedded triangles, on the given algorithmic lattices. The average error rates of individual rules are in the range of 8.8% (R184) to 11.9% (R062), and the average error rate for all the rules was 10.6%. Interpretation of elementary functions demonstrated through DNA algorithmic patterns could be extended to more complicated functions, which may lead to new insights for achieving the final answers of functions with experimentally obtained patterns.

Identification and characterization of saikosaponins as antagonists of transient receptor potential A1 channel.

Neuropathic pain is associated with an increased sensitivity to painful stimuli or abnormal sensitivity to otherwise innocuous stimuli. However, in addition to adverse effects, currently available drugs have shown limited response in patients with neuropathic pain, which provides a rationale to explore new drug classes acting on novel targets and with better efficacy and safety profiles. Here, we found that saikosaponins potently inhibit agonist-induced activation of the transient receptor potential A1 (TRPA1) channel, which has been reported to mediate neuropathic pain by sensing a variety of chemical irritants. Molecular docking and site-directed mutagenesis analyses suggested that saikosaponins bind to the hydrophobic pocket in TRPA1 near the Asn855 residue, which, when mutated to Ser, was previously associated with enhanced pain perception in humans. In support of these findings, saikosaponin D significantly attenuated agonist-induced nociceptive responses and vincristine-induced mechanical hypersensitivity in mice. These results indicate that saikosaponins are TRPA1 antagonists and provide a basis for further elaboration of saikosaponin derivatives for the development of new therapeutics for neuropathic pain.

Edgeworthia papyrifera Regulates Osteoblast and Osteoclast Differentiation In Vitro and Exhibits Anti-osteoporosis Activity in Animal Models of Osteoporosis.

Osteoporosis is a clinical condition characterized by low bone strength that leads to an increased risk of fracture. Strategies for the treatment of osteoporosis involve inhibition of bone resorption by osteoclasts and an increase of bone formation by osteoblasts. Here, we identified the extract derived from the stem part of Edgeworthia papyrifera that enhanced differentiation of MC3T3-E1 cells to osteoblast-like cells and inhibited osteoclast differentiation of RAW 264.7 cells in vitro. In support of our observation, rutin and daphnoretin, which were previously reported to inhibit osteoclast differentiation, were identified in E. papyrifera extract. In an animal model of osteoporosis, the ovariectomy-induced increases in bone resorption biomarkers such as pyridinoline and tartrate-resistant acid phosphatase were significantly reduced by E. papyrifera extract administration at 25.6 and 48.1%, respectively. Furthermore, the ovariectomy-induced bone loss in animal models of osteoporosis was significantly prevented by the administration of E. papyrifera in our study. Taking these observations into account, we suggest that E. papyrifera is an interesting candidate for further exploration as an anti-osteoporotic agent.

Down-regulation of p21-activated serine/threonine kinase 1 is involved in loss of mesencephalic dopamine neurons.

BACKGROUND: Although the roles of p21-activated serine/threonine kinase 1 (PAK1) have been reported in some neurodegenerative diseases, details regarding neurodegeneration are still limited. Hence, we tried to determine the role of PAK1 and molecular mechanisms of neuronal death involved in neurodegeneration. RESULTS: Expression of a dominant-negative form of PAK1 (PAK1(H83,86L, K229R), PAK1-DN) decreased the cell viability and increased cell death induced by oxidative stress. Indeed, oxidative stress decreased the phosphorylation of PAK1 in neuroblastoma cells, cultured dopamine (DA) neurons, or rat midbrains. PAK1-DN reduced the level of Bcl-2 protein, through an ubiquitin/proteasome-dependent mechanism. The level of Bcl-2 may be regulated by PAK1-ERK signaling and/or PAK1, directly. Conversely, expression of an active form of PAK1 (PAK1(T423E), PAK1-CA) could recover both loss of DA neurons in the substantia nigra (SN) and behavioral defects in a 6-OHDA-induced hemiparkinsonian rat model. CONCLUSIONS: Our data suggest that the oxidative stress-induced down-regulation of PAK1 activity could be involved in the loss of mesencephalic DA neurons through modulation of neuronal death, suggesting a novel role of PAK1 as a molecular determinant and mechanisms in the pathogenesis of Parkinson's disease.

Discovery, Optimization, and Biological Evaluation of Sulfonamidoacetamides as an Inducer of Axon Regeneration.

Axon regeneration after injury in the central nervous system is hampered in part because if an age-dependent decline in the intrinsic axon growth potential, and one of the strategies to stimulate axon growth in injured neurons involves pharmacological manipulation of implicated signaling pathways. Here we report phenotypic cell-based screen of chemical libraries and structure-activity-guided optimization that resulted in the identification of compound 7p which promotes neurite outgrowth of cultured primary neurons derived from the hippocampus, cerebral cortex, and retina. In an animal model of optic nerve injury, compound 7p was shown to induce growth of GAP-43 positive axons, indicating that the in vitro neurite outgrowth activity of compound 7p translates into stimulation of axon regeneration in vivo. Further optimization of compound 7p and elucidation of the mechanisms by which it elicits axon regeneration in vivo will provide a rational basis for future efforts to enhance treatment strategies.

Identification and Characterization of Baicalin as a Phosphodiesterase 4 Inhibitor.

Asthma is a chronic inflammatory disease of lung airways, and pharmacological inhibitors of cyclic adenosine monophosphate-specific phosphodiesterase 4 (PDE4) have been considered as therapeutics for the treatment of asthma. However, development of PDE4 inhibitors in clinical trials has been hampered because of the severe side effects of non-selective PDE4 inhibitors. Here, screening of a plant extract library in conjunction with dereplication technology led to identification of baicalin as a new type of PDE4-selective inhibitor. We demonstrated that while rolipram inhibited the enzyme activity of a range of PDE4 subtypes in in vitro enzyme assays, baicalin selectively inhibited the enzyme activity of PDE4A and 4B. In addition, baicalin suppressed lipopolysaccharide-induced TNF-α expression in macrophage where PDE4B plays a key role in lipopolysaccharide-induced signaling. Furthermore, baicalin treatment in an animal model of allergic asthma reduced inflammatory cell infiltration and TNF-α levels in bronchoalveolar lavage fluids, indicating that the antiinflammatory effects of baicalin in vivo are attributable, in part, to its ability to inhibit PDE4.

Synthesis and in-vitro evaluation of 2-amino-4-arylthiazole as inhibitor of 3D polymerase against foot-and-mouth disease (FMD).

Foot-and-mouth disease (FMD) is a highly contagious vesicular disease of livestock caused by a highly variable RNA virus, foot-and-mouth disease virus (FMDV). One of the targets to suppress expansion of and to control FMD is 3D polymerase (FMDV 3Dpol). In this study, 2-amino-4-arylthiazole derivatives were synthesized and evaluated for their inhibitory activity against FMDV 3Dpol. Among them, compound 20i exhibited the most potent functional inhibition (IC50 = 0.39 µM) of FMDV 3D polymerase and compound 24a (EC50 = 13.09 µM) showed more potent antiviral activity than ribavirin (EC50 = 1367 µM) and T1105 (EC50 = 347 µM) with IBRS-2 cells infected by the FMDV O/SKR/2010 strain.

Membrane-Associated Transporter Protein (MATP) Regulates Melanosomal pH and Influences Tyrosinase Activity.

The SLC45A2 gene encodes a Membrane-Associated Transporter Protein (MATP). Mutations of this gene cause oculocutaneous albinism type 4 (OCA4). However, the molecular mechanism of its action in melanogenesis has not been elucidated. Here, we discuss the role of MATP in melanin production. The SLC45A2 gene is highly enriched in human melanocytes and melanoma cell lines, and its protein, MATP, is located in melanosomes. The knockdown of MATP using siRNAs reduced melanin content and tyrosinase activity without any morphological change in melanosomes or the expression of melanogenesis-related proteins. Interestingly, the knockdown of MATP significantly lowered the melanosomal pH, as verified through DAMP analysis, suggesting that MATP regulates melanosomal pH and therefore affects tyrosinase activity. Finally, we found that the reduction of tyrosinase activity associated with the knockdown of MATP was readily recovered by copper treatment in the in vitro L-DOPA oxidase activity assay of tyrosinase. Considering that copper is an important element for tyrosinase activity and that its binding to tyrosinase depends on melanosomal pH, MATP may play an important role in regulating tyrosinase activity via controlling melanosomal pH.

An agarose gel-based neurosphere culture system leads to enrichment of neuronal lineage cells in vitro.

Stem cell-based therapy holds great potential especially for neurological disorders. However, clinical applications await further understanding of many aspects of stem cell differentiation and development of technology enabling manipulation of stem cells into desired cell types in the central nervous system. Here, we developed a new method that leads to enrichment of neuronal lineage cells in neural stem cell cultures. The protocol involves cultivation of primary cells derived from the forebrains of rat E18 embryos above a layer of nonadhesive hard agarose gel in the form of neurospheres. In contrast to the neurospheres that were cultured above an anti-adhesive hydrogel layer, the primary cells that were cultured above a layer of agarose gel preferentially differentiated into ß-III tubulin-positive neurons when allowed to undergo differentiation in vitro.In an effort to investigate the mechanism behind this observation, we found that the gene expression of a vertebrate neuronal determination gene (neurogenin1) was enhanced in the neurospheres that proliferated above a layer of agarose gel as compared with the control, and the gene expression level of neurogenin1 was quite well correlated with the rigidity of agarose gel. These results indicate that agarose gel can contribute, at least in part, to enrich neuronal progenitors and immature postmitotic neurons during neurosphere formation and may provide additional information to establish efficient protocols for the neural stem cell-based study.

Molecular pathogenesis of spondylocheirodysplastic Ehlers-Danlos syndrome caused by mutant ZIP13 proteins.

The zinc transporter protein ZIP13 plays critical roles in bone, tooth, and connective tissue development, and its dysfunction is responsible for the spondylocheirodysplastic form of Ehlers-Danlos syndrome (SCD-EDS, OMIM 612350). Here, we report the molecular pathogenic mechanism of SCD-EDS caused by two different mutant ZIP13 proteins found in human patients: ZIP13(G64D), in which Gly at amino acid position 64 is replaced by Asp, and ZIP13(ΔFLA), which contains a deletion of Phe-Leu-Ala. We demonstrated that both the ZIP13(G64D) and ZIP13(ΔFLA) protein levels are decreased by degradation via the valosin-containing protein (VCP)-linked ubiquitin proteasome pathway. The inhibition of degradation pathways rescued the protein expression levels, resulting in improved intracellular Zn homeostasis. Our findings uncover the pathogenic mechanisms elicited by mutant ZIP13 proteins. Further elucidation of these degradation processes may lead to novel therapeutic targets for SCD-EDS.

Anti-obesity phenotypic screening looking to increase OBR cell surface expression.

The leptin receptor, OBR, is involved in the regulation of whole-body energy homeostasis. Most obese people are resistant to leptin and do not respond to the hormone. The prevention and reversal of leptin resistance is one of the major current goals of obesity research. We showed previously that increased OBR cell surface expression concomitantly increases cellular leptin signaling and prevents obesity development in mice. Improvement of OBR cell surface expression can thus be considered as an interesting anti-obesity therapeutic strategy. To identify compounds that increase the surface expression of OBR, we developed a cell-based, phenotypic assay to perform a high-content screen (HCS) against a library of 50,000 chemical compounds. We identified 67 compounds that increased OBR cell surface expression with AC50 values in the low micromolar range and no effect on total OBR expression and cellular toxicity. Compounds were classified into 16 chemical clusters, of which 4 potentiated leptin-promoted signaling through the JAK2/STAT3 pathway. In conclusion, development of a robust phenotypic screening approach resulted in the discovery of four new scaffolds that demonstrate the desired biological activity and could constitute an original therapeutic solution against obesity and associated disorders.

Dendritic localization and a cis-acting dendritic targeting element of Kv4.2 mRNA.

Kv4.2, a pore-forming α-subunit of voltage-gated A-type potassium channels, is expressed abundantly in the soma and dendrites of hippocampal neurons, and is responsible for somatodendritic I(A) current. Recent studies have suggested that changes in the surface levels of Kv4.2 potassium channels might be relevant to synaptic plasticity. Although the function and expression of Kv4.2 protein have been extensively studied, the dendritic localization of Kv4.2 mRNA is not well described. In this study, Kv4.2 mRNAs were shown to be localized in the dendrites near postsynaptic regions. The dendritic transport of Kv4.2 mRNAs were mediated by microtubule- based movement. The 500 nucleotides of specific regions within the 3'-untranslated region of Kv4.2 mRNA were found to be necessary and sufficient for its dendritic localization. Collectively, these results suggest that the dendritic localization of Kv4.2 mRNAs might regulate the dendritic surface level of Kv4.2 channels and synaptic plasticity.

Apolipoprotein E mRNA is transported to dendrites and may have a role in synaptic structural plasticity.

Although the dendritic localization and translation of a subset of mRNAs plays a pivotal role in synaptic plasticity, the dendritic mRNAs and their functions have been only minimally characterized thus far. In this study, we isolated mRNAs from Staufen2-containing ribonucleoprotein complexes, which function as modules for the transport of mRNA to the dendrites, and then constructed a cDNA library. Apolipoprotein E gene (APOE) mRNA was isolated from the dendritic mRNA-specific cDNA library. The specific localization of APOE mRNA was evaluated via in situ hybridization. The specific regions involved in the dendritic transport of APOE mRNA were determined using a visualization system employing green fluorescent protein-tagged bacteriophage MS2 RNA-binding protein. As a result, the proximal N-terminal or C-terminal regions of the ApoE-coding sequences were determined to be sufficient for dendritic transport. The level of dendritic APOE mRNA was significantly increased by depolarization-induced neuronal activity, but was reduced in the cell body regions. We assessed the functions of neuronal ApoE. The reduction of ganglioside GM1 by cholesterol depletion was completely blocked by ApoE over-expression. In addition, ApoE over-expression increased the immunoreactivity of the post-synaptic density 95 kDa antibody in the dendrites. These findings indicate that neuronal ApoE may be relevant to lipid rafts or synaptic structural plasticity.

Role of mitogen-activated protein kinase (MAPK) docking sites on Staufen2 protein in dendritic mRNA transport.

Although transport and subsequent translation of dendritic mRNA play an important role in neuronal synaptic plasticity, the underlying mechanisms for modulating dendritic mRNA transport are almost completely unknown. In this study, we identified and characterized an interaction between Staufen2 and mitogen-activated protein kinase (MAPK) with co-immunoprecipitation assays. Staufen2 utilized a docking (D) site to interact with ERK1/2; deleting the D-site decreased colocalization of Staufen2 with immunoreactive ERK1/2 in the cell body regions of cultured hippocampal neurons, and it reduced the amount of Staufen2-containing RNP complexes in the distal dendrites. In addition, the deletion completely abolished the depolarization-induced increase of Staufen2-containing RNP complexes. These results suggest that the MAPK pathway could modulate dendritic mRNA transport through its interaction with Staufen2.

The transport of Staufen2-containing ribonucleoprotein complexes involves kinesin motor protein and is modulated by mitogen-activated protein kinase pathway.

There is increasing evidence showing that mRNA is transported to the neuronal dendrites in ribonucleoprotein (RNP) complexes or RNA granules, which are aggregates of mRNA, rRNA, ribosomal proteins, and RNA-binding proteins. In these RNP complexes, Staufen, a double-stranded RNA-binding protein, is believed to be a core component that plays a key role in the dendritic mRNA transport. This study investigated the molecular mechanisms of the dendritic mRNA transport using green fluorescent protein-tagged Staufen2 produced employing a Sindbis viral expression system. The kinesin heavy chain was found to be associated with Staufen2. The inhibition of kinesin resulted in a significant decrease in the level of dendritic transport of the Staufen2-containing RNP complexes in neurons under non-stimulating or stimulating conditions. This suggests that the dendritic transport of the Staufen2-containing RNP complexes use kinesin as a motor protein. A mitogen-activated protein kinase inhibitor, PD98059, inhibited the activity-induced increase in the amount of both the Staufen2-containing RNP complexes and Ca(2+)/calmodulin-dependent protein kinase II alpha-subunit mRNA in the distal dendrites of cultured hippocampal neurons. Overall, these results suggest that dendritic mRNA transport is mediated via the Staufen2 and kinesin motor proteins and might be modulated by the neuronal activity and mitogen-activated protein kinase pathway.