FcRγ- NK Cell Induction by Specific Cytomegalovirus and Expansion by Subclinical Viral Infections in Rhesus Macaques.

"Adaptive" NK cells, characterized by FcRγ deficiency and enhanced responsiveness to Ab-bound, virus-infected cells, have been found in certain hCMV-seropositive individuals. Because humans are exposed to numerous microbes and environmental agents, specific relationships between hCMV and FcRγ-deficient NK cells (also known as g-NK cells) have been challenging to define. Here, we show that a subgroup of rhesus CMV (RhCMV)-seropositive macaques possesses FcRγ-deficient NK cells that stably persist and display a phenotype resembling human FcRγ-deficient NK cells. Moreover, these macaque NK cells resembled human FcRγ-deficient NK cells with respect to functional characteristics, including enhanced responsiveness to RhCMV-infected target in an Ab-dependent manner and hyporesponsiveness to tumor and cytokine stimulation. These cells were not detected in specific pathogen-free (SPF) macaques free of RhCMV and six other viruses; however, experimental infection of SPF animals with RhCMV strain UCD59, but not RhCMV strain 68-1 or SIV, led to induction of FcRγ-deficient NK cells. In non-SPF macaques, coinfection by RhCMV with other common viruses was associated with higher frequencies of FcRγ-deficient NK cells. These results support a causal role for specific CMV strain(s) in the induction of FcRγ-deficient NK cells and suggest that coinfection by other viruses further expands this memory-like NK cell pool.

Influence of diluent on antimicrobial activity of cinnamon bark essential oil vapor against Staphylococcus aureus and Salmonella enterica on a laboratory medium and beef jerky.

The influence of chemical diluents on the antimicrobial activity of plant essential oil (EO) vapors was evaluated. We first determined if vapors generated from 22 chemical diluents not containing EO had antimicrobial activities. Ethyl ether vapor retarded the growth of S. aureus. The minimal inhibitory concentrations (MICs) and the minimal lethal concentrations (MLCs) of cinnamon bark EO vapor, which was diluted in and generated from 21 diluents, against S. aureus and S. enterica were determined. Cinnamon bark EO vapor showed significantly (P ≤ 0.05) lower MICs against S. aureus when diluted in dimethyl sulfoxide (DMSO), ethanol, ethyl acetate, or jojoba oil, and against S. enterica when diluted in DMSO, ethanol, or jojoba oil, compared to those in other diluents. We compared antimicrobial activities of cinnamon bark EO vapor diluted in DMSO, ethanol, ethyl acetate, or jojoba oil against S. aureus and S. enterica on beef jerky as a food model. Antimicrobial activity was significantly (P ≤ 0.05) higher when vaporized from DMSO. These results indicate that antimicrobial activity of cinnamon bark EO vapor may vary significantly (P ≤ 0.05) depending on the type of diluent from which it is vaporized. These observations provide basic information when developing food and food-contact surface decontamination strategies using EO vapors.

Effects of aerobic and resistance exercises on circulating apelin-12 and apelin-36 concentrations in obese middle-aged women: a randomized controlled trial.

BACKGROUND: The risk for obesity-related diseases increases with the prevalence of obesity. In obesity, adipokines secreted from adipose tissue induce inflammation, causing adverse effects. Recently, adipokines such as apelin, visfatin, and chemerin have been studied. Long-term resistance training improves health in middle-aged women by improving metabolic risk factors, body composition, and muscle strength. However, there is still a lack of evidence on the association of apelin concentration with different exercise types in middle-aged obese women This study aimed to investigate the effects of 8 weeks of aerobic and resistance exercises on apelin-12 and apelin-36 levels and thereby verify the effects of different exercise types in obese, middle-aged women. METHODS: Participants were middle-aged women aged 50-61 years, with no experience of systematic exercise in the last 6 months, and met the WHO obesity criteria for the Asia-Pacific region of waist circumference ≥ 80 cm and body fat percentage ≥ 30%. Subjects were selected and allocated to the aerobic exercise, resistance exercise, or no exercise group by block randomization. Body weight, body fat, and body mass index were measured by bioelectrical impedance analysis. Analysis of variance, the t-test, and Tukey's post-hoc test were performed. RESULTS: A total of 24 participants were selected with eight participants in each group. Both aerobic and resistance exercises were effective in altering the physical composition, showing significant decreases in weight, waist circumference, BMI, and body fat. The aerobic and resistance exercise group showed a significant, positive change in apelin-12 levels. CONCLUSIONS: In obese individuals, aerobic and resistance exercise were effective in improving obesity and reducing blood apelin-12 concentration, which is closely correlated with indicators of metabolic syndrome. Future research should focus on comparing the response of apelin to exercise in obese subjects treated with only dietary control and the response in the obese subjects of different ages and sex. TRIAL REGISTRATION: No. 1040917-201,506-BR-153-04 , Clinical Research Information Service (CRIS), Republic of Korea (05 October 2018, retrospectively registered).

G protein-coupled receptor kinase-2-deficient mice are protected from dextran sodium sulfate-induced acute colitis.

G protein-coupled receptor kinase 2 (GRK2) is a serine/threonine kinase and plays a key role in different disease processes. Previously, we showed that GRK2 knockdown enhances wound healing in colonic epithelial cells. Therefore, we hypothesized that ablation of GRK2 would protect mice from dextran sodium sulfate (DSS)-induced acute colitis. To test this, we administered DSS to wild-type (GRK2+/+) and GRK2 heterozygous (GRK+/-) mice in their drinking water for 7 days. As predicted, GRK2+/- mice were protected from colitis as demonstrated by decreased weight loss (20% loss in GRK2+/+ vs. 11% loss in GRK2+/-). lower disease activity index (GRK2+/+ 9.1 vs GRK2+/- 4.1), and increased colon lengths (GRK2+/+ 4.7 cm vs GRK2+/- 5.3 cm). To examine the mechanisms by which GRK2+/- mice are protected from colitis, we investigated expression of inflammatory genes in the colon as well as immune cell profiles in colonic lamina propria, mesenteric lymph node, and in bone marrow. Our results did not reveal differences in immune cell profiles between the two genotypes. However, expression of inflammatory genes was significantly decreased in DSS-treated GRK2+/- mice compared with GRK2+/+. To understand the mechanisms, we generated myeloid-specific GRK2 knockout mice and subjected them to DSS-induced colitis. Similar to whole body GRK2 heterozygous knockout mice, myeloid-specific knockout of GRK2 was sufficient for the protection from DSS-induced colitis. Together our results indicate that deficiency of GRK2 protects mice from DSS-induced colitis and further suggests that the mechanism of this effect is likely via GRK2 regulation of inflammatory genes in the myeloid cells.

Probing protein disorder and complexity at single-molecule resolution.

A substantial fraction of the human proteome encodes disordered proteins. Protein disorder is associated with a variety of cellular functions and misfunction, and is therefore of clear import to biological systems. However, disorder lends itself to conformational flexibility and heterogeneity, rendering proteins which feature prominent disorder difficult to study using conventional structural biology methods. Here we discuss a few examples of how single-molecule methods are providing new insight into the biophysics and complexity of these proteins by avoiding ensemble averaging, thereby providing direct information about the complex distributions and dynamics of this important class of proteins. Examples of note include characterization of isolated IDPs in solution as collapsed and dynamic species, detailed insight into complex IDP folding landscapes, and new information about how tunable regulation of structure-mediated binding cooperativity and consequent function can be achieved through protein disorder. With these exciting advances in view, we conclude with a discussion of a few complementary and emerging single-molecule efforts of particular promise, including complementary and enhanced methodologies for studying disorder in proteins, and experiments to investigate the potential role for IDP-induced phase separation as a critical functional element in biological systems.

Role of G protein-coupled receptor kinase-6 in Escherichia coli lung infection model in mice.

G protein-coupled receptor kinase-6 (GRK6) is a serine/threonine kinase that is important in inflammatory processes. In this study, we examined the role of GRK6 in Escherichia coli-induced lung infection and inflammation using GRK6 knockout (KO) and wild-type (WT) mice. Intratracheal instillation of E. coli significantly enhanced bacterial load in the bronchoalveolar lavage (BAL) of KO compared with WT mice. Reduced bacterial clearance in the KO mice was not due to an intrinsic defect in neutrophil phagocytosis or killing but as a result of reduced neutrophil numbers in the KO BAL. Interestingly, neutrophil numbers in the lung were increased in the KO compared with WT mice, suggesting a potential dysfunction in transepithelial migration of neutrophils from the lungs to the bronchoalveolar space. This effect was selective for lung tissue because peritoneal neutrophil numbers were similar between the two genotypes following peritoneal infection. Although neutrophil expression of CXCR2/CXCR3 was similar between WT and KO, IL-17A expression was higher in the KO compared with WT mice. These results suggest that enhanced neutrophil count in the KO lungs but reduced numbers in BAL are likely due to transepithelial migration defect and/or altered chemokines/cytokines. Together, our studies suggest a previously unrecognized and novel role for GRK6 in neutrophil migration specific to pulmonary tissue during bacterial infection.

Molecular Markers for Interspecies Transmission of Avian Influenza Viruses in Mammalian Hosts.

In the last decade, a wide range of avian influenza viruses (AIVs) have infected various mammalian hosts and continuously threaten both human and animal health. It is a result of overcoming the inter-species barrier which is mostly associated with gene reassortment and accumulation of mutations in their gene segments. Several recent studies have shed insights into the phenotypic and genetic changes that are involved in the interspecies transmission of AIVs. These studies have a major focus on transmission from avian to mammalian species due to the high zoonotic potential of the viruses. As more mammalian species have been infected with these viruses, there is higher risk of genetic evolution of these viruses that may lead to the next human pandemic which represents and raises public health concern. Thus, understanding the mechanism of interspecies transmission and molecular determinants through which the emerging AIVs can acquire the ability to transmit to humans and other mammals is an important key in evaluating the potential risk caused by AIVs among humans. Here, we summarize previous and recent studies on molecular markers that are specifically involved in the transmission of avian-derived influenza viruses to various mammalian hosts including humans, pigs, horses, dogs, and marine mammals.

Binding of NFκB Appears to Twist the Ankyrin Repeat Domain of IκBα.

Total internal reflection fluorescence-based single-molecule Förster resonance energy transfer (FRET) measurements were previously carried out on the ankyrin repeat domain (ARD) of IκBα, the temporally regulated inhibitor of canonical NFκB signaling. Under native conditions, most of the IκBα molecules showed stable, high FRET signals consistent with distances between the fluorophores estimated from the crystal structures of the NFκB(RelA/p50)-IκBα complex. Similar high FRET efficiencies were found when the IκBα molecules were either free or in complex with NFκB(RelA/p50), and were interpreted as being consistent with the crystallographically observed ARD structure. An exception to this was observed when the donor and acceptor fluorophores were attached in AR3 (residue 166) and AR6 (residue 262). Surprisingly, the FRET efficiency was lower for the bound IκBα molecules (0.67) than for the free IκBα molecules (0.74), apparently indicating that binding of NFκB(RelA/p50) stretches the ARD of IκBα. Here, we conducted confocal-based single-molecule FRET studies to investigate this phenomenon in greater detail. The results not only recapitulated the apparent stretching of the ARD but also showed that the effect was more pronounced when the N-terminal domains (NTDs) of both RelA and p50 were present, even though the interface between NFκB(RelA/p50) and IκBα encompasses only the dimerization domains. We also performed mass spectrometry-detected amide hydrogen/deuterium exchange (HDXMS) experiments on IκBα as well as IκBα bound to dimerization-domain-only constructs or full-length NFκB(RelA/p50). Although we expected the stretched IκBα to have regions with increased exchange, instead the HDXMS experiments showed decreases in exchange in AR3 and AR6 that were more pronounced when the NFκB NTDs were present. Simulations of the interaction recapitulated the increased distance between residues 166 and 262, and also provide a plausible mechanism for a twisting of the IκBα ARD induced by interactions of the IκBα proline-glutamate-serine-threonine-rich sequence with positively charged residues in the RelA NTD.

Non-Hematopoietic ß-Arrestin1 Confers Protection Against Experimental Colitis.

ß-Arrestins are multifunctional scaffolding proteins that modulate G protein-coupled receptor (GPCR)-dependent and -independent cell signaling pathways in various types of cells. We recently demonstrated that ß-arrestin1 (ß-arr1) deficiency strikingly attenuates dextran sodium sulfate (DSS)-induced colitis in mice. Since DSS-induced colitis is in part dependent on gut epithelial injury, we examined the role of ß-arr1 in intestinal epithelial cells (IECs) using a colon epithelial cell line, SW480 cells. Surprisingly, we found that knockdown of ß-arr1 in SW480 cells enhanced epithelial cell death via a caspase-3-dependent process. To understand the in vivo relevance and potential cell type-specific role of ß-arr1 in colitis development, we generated bone marrow chimeras with ß-arr1 deficiency in either the hematopoietic or non-hematopoietic compartment. Reconstituted chimeric mice were then subjected to DSS-induced colitis. Similar to our previous findings, ß-arr1 deficiency in the hematopoietic compartment protected mice from DSS-induced colitis. However, consistent with the role of ß-arr1 in epithelial apoptosis in vitro, non-hematopoietic ß-arr1 deficiency led to an exacerbated colitis phenotype. To further understand signaling mechanisms, we examined the effect of ß-arr1 on TNF-α-mediated NFκB and MAPK pathways. Our results demonstrate that ß-arr1 has a critical role in modulating ERK, JNK and p38 MAPK pathways mediated by TNF-α in IECs. Together, our results show that ß-arr1-dependent signaling in hematopoietic and non-hematopoietic cells differentially regulates colitis pathogenesis and further demonstrates that ß-arr1 in epithelial cells inhibits TNF-α-induced cell death pathways.

Dual Unnatural Amino Acid Incorporation and Click-Chemistry Labeling to Enable Single-Molecule FRET Studies of p97 Folding.

Many cellular functions are critically dependent on the folding of complex multimeric proteins, such as p97, a hexameric multidomain AAA+ chaperone. Given the complex architecture of p97, single-molecule (sm) FRET would be a powerful tool for studying folding while avoiding ensemble averaging. However, dual site-specific labeling of such a large protein for smFRET is a significant challenge. Here, we address this issue by using bioorthogonal azide-alkyne chemistry to attach an smFRET dye pair to site-specifically incorporated unnatural amino acids, allowing us to generate p97 variants reporting on inter- or intradomain structural features. An initial proof-of-principle set of smFRET results demonstrated the strengths of this labeling method. Our results highlight this as a powerful tool for structural studies of p97 and other large protein machines.

Optimization of treatment with recombinant FGF-2 for proliferation and differentiation of human dental stem cells, mesenchymal stem cells, and osteoblasts.

Basic fibroblast growth factor (bFGF or FGF-2) is widely used to modulate the proliferation and differentiation of certain cell types. An expression and purification system for recombinant human FGF-2 in Escherichia coli was established for the purpose of securing a continuous supply of this protein. The purified recombinant FGF-2 significantly increased the population of human embryonic stem cells. The optimal concentrations of FGF-2 for cell proliferative induction in various adult stem cells including human dental pulp stem cells, full term human periodontal ligament stem cells, human gingival fibroblasts, mesenchymal stem cells, and osteogenic oseosarcoma were established in a dose-dependent manner. When cells were treated with recombinant FGF-2 for 6 days before osteogenic induction, the mRNA expression of the bone markers was upregulated in cells originated from human dental pulp tissue, indicating that pretreatment with FGF-2 during culture increase stem cell/progenitor population and osteogenic potential.

Probiotic L. reuteri treatment prevents bone loss in a menopausal ovariectomized mouse model.

Estrogen deficiency is a major risk factor for osteoporosis that is associated with bone inflammation and resorption. Half of women over the age of 50 will experience an osteoporosis related fracture in their lifetime, thus novel therapies are needed to combat post-menopausal bone loss. Recent studies suggest an important role for gut-bone signaling pathways and the microbiota in regulating bone health. Given that the bacterium Lactobacillus reuteri ATCC PTA 6475 (L. reuteri) secretes beneficial immunomodulatory factors, we examined if this candidate probiotic could reduce bone loss associated with estrogen deficiency in an ovariectomized (Ovx) mouse menopausal model. Strikingly, L. reuteri treatment significantly protected Ovx mice from bone loss. Osteoclast bone resorption markers and activators (Trap5 and RANKL) as well as osteoclastogenesis are significantly decreased in L. reuteri-treated mice. Consistent with this, L. reuteri suppressed Ovx-induced increases in bone marrow CD4+ T-lymphocytes (which promote osteoclastogenesis) and directly suppressed osteoclastogenesis in vitro. We also identified that L. reuteri treatment modifies microbial communities in the Ovx mouse gut. Together, our studies demonstrate that L. reuteri treatment suppresses bone resorption and loss associated with estrogen deficiency. Thus, L. reuteri treatment may be a straightforward and cost-effective approach to reduce post-menopausal bone loss.

Lithium chloride induces TNFα in mouse macrophages via MEK-ERK-dependent pathway.

Lithium (Li) is one of the currently prescribed drugs for bipolar disorders (BPDs) and has many neuro-regulatory and immune-modulating properties. Because many neuro-pathological diseases including BPDs have been associated with some level of inflammation, Li's effect on inflammation may have some crucial consequences. Even though Li has been shown to have pro- and anti-inflammatory activities in different cell models, mechanisms involved in these effects are not well understood. Moreover, Li's effect on inflammation in the presence of activators of Toll-like receptors (TLRs), especially TLR-2 (that activates MyD88-dependent pathway) and TLR-3 (that activates TRIF-dependent pathway) is not known. Here we tested the role of Li in the presence and absence of TLR2, and TLR3 on MAPK and NFκB pathways and the consequent production of tumor necrosis factor-α (TNFα) in Raw264.7 macrophages. Our results indicate that Li enhances TNFα production both in the absence and presence of TLR stimulation. Interestingly, Li differentially modulates MAPK and NFκB pathways in the absence and presence of TLR2/3 ligands. Our results further indicate that the effect of Li on TNFα occurs at the post-transcriptional level. Together, these studies demonstrate that Li induces TNFα production in macrophages and that it modulates signaling at different levels depending on the presence or absence of TLR2/3 stimulation.

ß-Arrestin-1 deficiency protects mice from experimental colitis.

ß-Arrestins are intracellular scaffolding proteins that modulate specific cell signaling pathways. Recent studies, in both cell culture and in vivo models, have demonstrated an important role for ß-arrestin-1 in inflammation. However, the role of ß-arrestin-1 in the pathogenesis of inflammatory bowel disease (IBD) is not known. Our goal was to investigate the role of ß-arrestin-1 in IBD using mouse models of colitis. To this end, we subjected wild-type (WT) and ß-arrestin-1 knockout (ß-arr-1(-/-)) mice to colitis induced by trinitrobenzenesulfonic acid or dextran sulfate sodium and examined the clinical signs, gross pathology, and histopathology of the colon, as well as inflammatory components. The ß-arr-1(-/-) mice displayed significantly attenuated colitis, compared with WT mice, in both models. Consistent with the phenotypic observations, histological examination of the colon revealed attenuated disease pathology in the ß-arr-1(-/-) mice. Our results further demonstrate that ß-arr-1(-/-) mice are deficient in IL-6 expression in the colon, but have higher expression of the anti-inflammatory IL-10 family of cytokines. Our results also demonstrate diminished ERK and NFκB pathways in the colons of ß-arr-1(-/-) mice, compared with WT mice. Taken together, our results demonstrate that decreased IL-6 production and enhanced IL-10 and IL-22 production in ß-arrestin-1-deficient mice likely lead to attenuated gut inflammation.

Identification of human NK cells that are deficient for signaling adaptor FcRγ and specialized for antibody-dependent immune functions.

NK cells respond to tumor and virus-infected cells directly through several activation receptors, including natural cytotoxicity receptors, or indirectly through the activating Fc receptor CD16 for antibody-coated cells. Triggering of NK-cell effector functions through these receptors depends on physically associated transmembrane signaling adaptors, such as FcRγ (also known as FcεRIγ) and CD3ζ, both of which have been traditionally believed to be expressed by all mature NK cells. However, we have identified a distinct subset of human NK cells that are deficient for FcRγ expression but express normal levels of CD3ζ. FcRγ-deficient NK cells were readily detectable in about one-third of the healthy individuals examined. The deficiency was confined to the CD56(dim) population and was due to low FcRγ mRNA. FcRγ-deficient NK cells displayed dramatically reduced expression of the natural cytotoxicity receptors NKp46 and NKp30 but still expressed substantial levels of CD16. Compared to FcRγ-expressing NK cells, FcRγ-deficient NK cells showed poor direct reactivity toward tumor targets as measured by cytokine production and degranulation. Unexpectedly, however, FcRγ-deficient NK cells exhibited significantly more robust responsiveness upon stimulation through CD16, particularly for cytokine production, compared to FcRγ-expressing NK cells. Thus, our study reveals FcRγ-deficient NK cells as a novel subset of human NK cells that have remarkably potent responses toward antibody-coated targets. These findings also illustrate a differential contribution of FcRγ and CD3ζ for the expression and functional activity of their associated receptors.

Reyranella soli sp. nov., isolated from forest soil, and emended description of the genus Reyranella Pagnier et al. 2011.

A Gram-stain-negative, non-motile, rod-shaped bacterial strain, designated KIS14-15(T), was isolated from forest soil of Baengnyeong Island in the Yellow Sea in Korea and its taxonomic position was investigated by using a polyphasic study. Strain KIS14-15(T) grew optimally at 30 °C, at pH 6.0-7.0 and without NaCl. In the neighbour-joining phylogenetic tree based on 16S rRNA gene sequences, strain KIS14-15(T) formed a cluster with the strains of Reyranella massiliensis with a bootstrap resampling value of 100%. Strain KIS14-15(T) exhibited 16S rRNA gene sequence similarity values of 98.0% to R. massiliensis 521(T) and of less than 89% to the type strains of other taxa. The mean level of DNA-DNA relatedness between strain KIS14-15(T) and R. massiliensis KACC 16548(T) was 21% (reciprocal, 24%). The predominant ubiquinone found in strain KIS14-15(T) and R. massiliensis KACC 16548(T) was ubiquinone-10 (Q-10). The predominant fatty acids of strain KIS14-15(T) and R. massiliensis KACC 16548(T) were C(18:1)ω7c, C(18:1) 2-OH and 11-methyl C(18:1)ω7c. Total polar lipids of strain KIS14-15(T) were phosphatidylmonomethylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unknown aminolipid and one unknown lipid. Differential phenotypic properties, together with phylogenetic and genetic distinctiveness, demonstrated that strain KIS14-15(T) is distinguishable from R. massiliensis. On the basis of the data presented, strain KIS14-15(T) is considered to represent a novel species of the genus Reyranella, for which the name Reyranella soli sp. nov. is proposed. The type strain is KIS14-15(T) ( = KACC 13034(T) =NBRC 108950(T)).

Highly Resilient Dual-Crosslinked Hydrogel Adhesives Based on a Dopamine-Modified Crosslinker.

Hydrogels are promising material for wound dressing and tissue engineering. However, owing to their low tissue adhesion in a moist environment and lack of flexibility, hydrogels are still not widely applied in movable parts, such as joints. Herein, we report a dual-crosslinked hydrogel adhesive using a dopamine-modified and acrylate-terminated crosslinker, tri(ethylene glycol) diacrylate-dopamine crosslinker (TDC). The covalent crosslinking was formed by photopolymerization between acrylic acid (AA) and TDC, and the noncovalent crosslinking was formed by intermolecular dopamine-dopamine and dopamine-AA interactions. Our resultant hydrogel demonstrated strong tissue adhesion in a moist environment (approximately 71 kPa) and high mechanical resilience (approximately 94%) with immediate recovery at a 200% strain rate. Moreover, it accelerated wound healing upon dressing the wound site properly. Our study provides the potential for advanced polymer synthesis by introducing a functional crosslinking agent.

Animal Models of COVID-19: Nonhuman Primates.

With the advent of the novel SARS-CoV-2, the entire world has been thrown into chaos with severe disruptions from a normal life. While the entire world was going chaotic, the researchers throughout the world were struggling to contribute to the best of their capabilities to advance the understanding of this new pandemic and fast track the development of novel therapeutics and vaccines. While various animal models have helped a lot to understand the basic physiology, nonhman primates have been promising and much more successful in modelling human diseases compared to other available clinical models. Here we describe the different aspects of modelling the SARS-CoV-2 infection in NHPs along with the associated methods used in NHP immunology.

G-protein coupled receptor kinase 5 mediates lipopolysaccharide-induced NFκB activation in primary macrophages and modulates inflammation in vivo in mice.

G-protein coupled receptor kinase-5 (GRK5) is a serine/threonine kinase discovered for its role in the regulation of G-protein coupled receptor signaling. Recent studies have shown that GRK5 is also an important regulator of signaling pathways stimulated by non-GPCRs. This study was undertaken to determine the physiological role of GRK5 in Toll-like receptor-4-induced inflammatory signaling pathways in vivo and in vitro. Using mice genetically deficient in GRK5 (GRK5(-/-) ) we demonstrate here that GRK5 is an important positive regulator of lipopolysaccharide (LPS, a TLR4 agonist)-induced inflammatory cytokine and chemokine production in vivo. Consistent with this role, LPS-induced neutrophil infiltration in the lungs (assessed by myeloperoxidase activity) was markedly attenuated in the GRK5(-/-) mice compared to the GRK5(+/+) mice. Similar to the in vivo studies, primary macrophages from GRK5(-/-) mice showed attenuated cytokine production in response to LPS. Our results also identify TLR4-induced NFκB pathway in macrophages to be selectively regulated by GRK5. LPS-induced IκBα phosphorylation, NFκB p65 nuclear translocation, and NFκB binding were markedly attenuated in GRK5(-/-) macrophages. Together, our findings demonstrate that GRK5 is a positive regulator of TLR4-induced IκBα-NFκB pathway as well as a key modulator of LPS-induced inflammatory response.

Photoresponsive, switchable, pressure-sensitive adhesives: influence of UV intensity and hydrocarbon chain length of low molecular weight azobenzene compounds.

Unlike traditional adhesives with a fixed adhesive force, switchable adhesives, which have an adhesive force that can be adjusted by external stimuli, are specifically designed to be released according to user demand, or to enable the transfer of fine electronic devices. Previously developed switchable adhesives have limitations such as a slow switching rate, narrow adhesion modulation range, or the lack of reusability. Thus, we fabricated switchable pressure-sensitive adhesives (PSAs) that can overcome these limitations. The adhesive force of each switchable PSA, which comprises an azobenzene-containing acrylic polymer and low molecular weight compounds, was designed to be activated/deactivated via ultraviolet (UV) and visible light irradiation. The adhesive force and UV intensity required for the switch were found to be dependent on the aliphatic chain length of the compound. The adhesive force of the SP-C10, i.e., a switchable PSA containing a azobenzene compound with an aliphatic chain of 10 hydrocarbons, increased to 3.5 N from nearly zero in response to only 30 s of low-level (25 mW cm-2) UV irradiation. Additionally, SP-C10 did not lose its adhesive force even after 30 cycles of repeated adhesion switching. The mechanism of adhesion switching influenced by UV intensity and the structure of low molecular weight azobenzene compounds are also reported.