Earticle

Sharing economy platforms, represented by Uber or Airbnb have recently grown rapidly. Unlike the traditional online p2p market, providers in sharing economy platform become part of the service and have a significant impact on the overall service experience. Consequently, consumers should explore not only the product but also providers’ information before making a purchase to reduce the uncertainty of the overall quality of service. Furthermore, frequent crimes in Airbnb and Uber are increasing the importance of knowing provider information. However, the information of providers exposed on most platforms is limited to self-introduction and profile pictures. Accordingly, users should rely on this limited information to reduce service uncertainty. In this paper, we found that having a group-type host profile picture has a positive effect on the reservation rate in Airbnb. In addition, the impact of profile pictures is stronger in the cities with the high crime rate. The findings demonstrate that hosts’ group-type profile picture could serve as a signal on safety in sharing economy platforms.

The objective of this study was to determine the effect of different stocker management programs on skeletal muscle development and growth characteristics, satellite cell (SC) activity in growing-finishing beef cattle as well as the effects of SC-conditioned media on preadipocyte gene expression and differentiation. Fall-weaned Angus steers (n = 76; 258 ± 28 kg) were randomly assigned to 1 of 4 stocker production systems: 1) grazing dormant native range (NR) supplemented with a 40% CP cottonseed meal-based supplement (1.02 kg ? steer?1 ? d?1) followed by long-season summer grazing (CON, 0.46 kg/d); 2) grazing dormant NR supplemented with a ground corn and soybean meal-based supplement fed at 1% of BW followed by short-season summer grazing (CORN, 0.61 kg/d); 3) grazing winter wheat pasture (WP) at high stocking density (3.21 steers/ha) to achieve a moderate rate of gain (LGWP, 0.83 kg/d); and 4) grazing winter WP at low stocking density (0.99 steers/ha) to achieve a high rate of gain (HGWP, 1.29 kg/d). At the end of the stocker (intermediate harvest, IH) and finishing (final harvest, FH) phases, 4 steers / treatment were harvested and longissimus muscles (LM) sampled for cryohistological immunofluorescence analysis and SC culture assays. At IH, WP steers had greater LM fiber cross-sectional area than NR steers; however, at FH, the opposite was observed (p < 0.0001). At IH, CORN steers had the lowest Myf-5+:Pax7+ SC density (p = 0.020), while LGWP steers had the most Pax7+ SC (p = 0.043). At FH, CON steers had the highest LM capillary density (p = 0.003) and their cultured SC differentiated more readily than all other treatments (p = 0.017). At FH, Pax7 mRNA was more abundant in 14 d-old SC cultures from HGWP cattle (p = 0.03). Preadipocytes exposed to culture media from proliferating SC cultures from WP cattle isolated at FH had more PPARγ (p = 0.037) and less FABP4 (p = 0.030) mRNA expression compared with NR cattle. These data suggest that different stocker management strategies can impact skeletal muscle growth, SC function, and potentially impact marbling development in growing-finishing beef cattle.

Recent progress has been made to establish intestinal organoids for an in vitro model as a potential alternative to an in vivo system in animals. We previously reported a reliable method for the isolation of intestinal crypts from the small intestine and robust three-dimensional (3D) expansion of intestinal organoids (basal-out) in adult bovines. The present study aimed to establish next-generation intestinal organoids for practical applications in disease modeling-based host-pathogen interactions and feed efficiency measurements. In this study, we developed a rapid and convenient method for the efficient generation of intestinal organoids through the modulation of the Wnt signaling pathway and continuous apical-out intestinal organoids. Remarkably, the intestinal epithelium only takes 3-4 days to undergo CHIR (1 µM) treatment as a Wnt activator, which is much shorter than that required for spontaneous differentiation (7 days). Subsequently, we successfully established an apical-out bovine intestinal organoid culture system through suspension culture without Matrigel matrix, indicating an apical-out membrane on the surface. Collectively, these results demonstrate the efficient generation and next-generation of bovine intestinal organoids and will facilitate their potential use for various purposes, such as disease modeling, in the field of animal biotechnology.

S-adenosylhomocysteine hydrolase-like protein 1 (AHCYL1), also known as IP3 receptor- binding protein released with IP3 (IRBIT), regulates IP3-induced Ca2+ release in the cytoplasm of cells and, therefore, is likely to be an important gene regulating various biological processes in the oviduct of chickens. However, the identification of the AHCYL1 gene in chickens has not been investigated. Therefore, the objectives of this study were to examine the tissue- and cell-specific expression of AHCYL1 gene in chicken organs, especially in reproductive organ, and determine functional actions of AHCYL1 in chicken oviduct development via estrogen. The results indicated that AHCYL1 mRNA is expressed in chicken reproductive organs and DES(diethylstilbesterol, a synthetic estrogen agonist) stimulates the cell specific expression of AHCYL1 in immature chicken oviduct. These results suggest that AHCYL1 is a novel estrogen-stimulated gene associated with development of the chicken oviduct. Next, in the present study, we show that inhibition of Erk1/2 can block DES-induced AHCYL1 expression. Also, we found that knockdown of AHCYL1 expression down-regulates expression of oviduct specific genes and AHCYL1 expression is regulated at the post-transcriptional level by specific miRNAs. These results strongly suggest that estrogen-mediated AHCYL1 gene expression plays a crucial role in growth, differentiation and function of the hen oviduct. Also, our results will be useful for understanding the fundamental mechanism(s) of estrogen action responsible for development of hen oviduct. This research was funded by the World Class University (WCU) program (R31-10056), Basic Science Research Program (2010-0013078) through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science, and Technology and by the Next-Generation BioGreen 21 Program (No.PJ008142), Rural Development Administration, Republic of Korea.

Maternal separation in the developmental stage has a negative influ-ence on brain development and causes depression. The extracellular ligand, Wnt, and its receptors play an important role in axis formation and neural development. Exercise inhibits apoptosis, increases cell proliferation, and exerts antidepressive effect. In this study, the effect of treadmill exercise on the maternal separation-induced depression was investigated in the aspect of Wnt signaling pathway. The maternal sep-aration started on the postnatal day 14. The rat pups in the exercise groups were forced to run on a treadmill for 30 min once a day from postnatal day 21 to postnatal day 34. The rat pups in the maternal sepa-ration and fluoxetine-treated group were intraperitoneally injected with 5-mg/kg fluoxetine once a day from postnatal day 21 to postnatal day 34. Forced swimming test was performed to evaluate the depression level. Western blotting was performed for the expressions of Wnt sig-naling ligands, Wnt2 and Wnt3a, and Wnt signaling inhibitors, Dkk1, and sFRP3. Maternal separation showed depressive behaviors in the forced swimming test. Treadmill exercise alleviated depressive behaviors in the maternal separation rat pups. Expressions of Wnt2 and Wnt3a were decreased by maternal separation. Treadmill exercise alleviated mater-nal separation-induced reduction of Wnt2 and Wnt3a expressions. Ex-pressions of Dkk1 and sFRP3 in the hippocampus were increased by maternal separation. Treadmill exercise alleviated maternal separa-tion-induced reduction of Dkk1 and sFRP3 expressions. Our study demonstrated that treadmill exercise activates Wnt signaling pathway, and then exerted antidepressive effect.

The purpose of this study was to determine whether treadmill walking exercise can improve mechanical allodynia through regulation of Wnt/β-catenin signaling in dorsal root ganglion (DRG) neurons at the early stage of regeneration after sciatic nerve injury (SNI). The experimental rats were divided into seven groups: the normal control, sedentary groups for 3-, 7-, and 14-day post crush (dpc), and exercise group for 3, 7, and 14 dpc. The rats in exercise groups performed treadmill walking exercise at a speed of 8 m/min for 20 min once a day according to ex-periment duration. For evaluating neuropathic pain-like behavior after SNI, the mechanical allodynia was examined by von Frey apparatus. And the expression levels of pain-related protein were identified in the cytoplasm or nucleus of DRG neurons using Western blot techniques. Mechanical allodynia was significantly ameliorated in the exercise group at 7 and 14 dpc. Treadmill exercise further decreased Wnt3a ex-pression at 3, 7, and 14 dpc compared to in the sedentary group. Also, phosphorylated-low-density lipoprotein receptor 6 was decreased in exercise groups at 3 and 14 dpc. Beta-catenin was significantly de-creased in exercise groups at 3 and 14 dpc compared to sedentary groups as well as treadmill exercise decreased translocation of β-cat-enin towards the nucleus of DRG neurons at 14 dpc. Our findings indi-cate that treadmill walking exercise may be an important regulator of neuropathic pain after peripheral nerve injury through delayed Wnt/β-catenin signaling pathway in DRG neurons.

The purpose of this study was to investigate whether combination of low-intensity exercise with bone marrow stromal cell (BMSC) trans-plantation could regulate protein kinas B (Akt)- mammalian target of rapamycin (mTOR) and Wnt3a-β-catenin signaling pathways for pre-vention of soleus muscle atrophy after sciatic nerve injury (SNI). The experimental rats divided into 5 groups (n=10): normal control group, SNI+sedentary group (SED), SNI+low-intensity treadmill exercise group (TEX), SNI+BMSC transplantation group (BMSC), SNI+TEX+BMSC transplantation group (TEX+BMSC). Sciatic nerve crush injury was ap-plied into the middle of thigh twice for 1 min and 30 sec at interval. Low-intensity treadmill exercise was comprised of walking at a speed of 4 to 8 m/min for 30 min once a day. cultured BMSC at a density of 5×106 in 50-μL phosphate-buffered saline was injected into the distal portion of the injured sciatic nerves. TEX+BMSC group dramatically up-regulated expression levels of growth-associated protein-43 in the in-jured sciatic nerve at 2 weeks postinjury. Also, although Akt and mTOR signaling pathway significantly increased in TEX and BMSC groups than SED group, TEX+BMSC group showed more potent increment on this signaling in soleus muscle after SNI. Lastly, Wnt3a and the nuclear translocation of β-catenin and nuclear factor-kappa B in soleus were increased by SNI, but TEX+BMSC group significantly downregulated activity of this signaling pathway in the nuclear cell lysate of soleus muscle. Present findings provide new information that combination of low-intensity treadmill exercise might be effective therapeutic ap-proach on restriction of soleus muscle atrophy after peripheral nerve injury.

The effect of combined approach of exercise training and bone marrow stromal cell (BMSC) engraftment on activation of brain-derived neuro-trophic factor (BDNF)-extracellular signal-regulated kinase 1 and 2 (ERK1/2)-cyclic adenosine monophosphate response element-binding protein (CREB) signaling pathway after sciatic nerve injury (SNI) was investigated. Sixty male Sprague-Dawley rats divided into the normal control, nonexercise (NEX), exercise training (EX), BMSC transplanta-tion (TP), and exercise training+BMSC transplantation (EX+TP) groups 4 weeks after SCI. Exercise training was carried out on the treadmill de-vice at 5–10 m/min for 20 min for 4 weeks. Single dose of 5×106 harvest-ed BMSC was injected into the injury area of the injured sciatic nerve. In order to evaluate induction levels of BDNF-ERK1/2-CREB signaling molecules in the whole cell and nuclear cell lysates of the injured sciat-ic nerve, we applied Western blot analysis. BDNF was significantly in-creased only in EX+TP compared to NEX, EX, and TP groups. Phospho-inositide-dependent kinase-1 was more increased in EX, TP, and EX+TP groups than NEX group, but EX+TP group showed the most upregula-tion of phosphorylated protein kinase B compared to other groups. In addition, in the whole cell lysate, phosphorylated ERK1/2, but not acti-vating transcription factor-3 (ATF-3) and phosphorylated CREB, was sig-nificantly increased in TP and EX+TP groups. In the nuclear cell lysate, ATF-3 and phosphorylated CREB were strongly activated in EX+TP group compared to EX group. Regular exercise training combined with BMSC engraftment would seem to be more effective in controlling activation of regeneration-related signaling pathway after SNI.

Particulate matters (PM), the main contributor to air pollution, have become a serious issue that threatens human’s health. Skin is the largest organ in humans, as well as the primary organ exposed to PM. Overexposure of PM induces skin damage. Diphlorethohydroxycarmalol (DPHC), an algal polyphenol with the potential of skin protection, has been isolated from the edible brown seaweed Ishige okamurae. The purpose of the present study is to investigate the protective eect of DPHC against PM (ERM-CZ100)-induced skin damage in human dermal fibroblasts (HDF) cells. The results indicated that DPHC significantly and dose-dependently reduced intracellular reactive oxygen species generation in HDF cells. In addition, DPHC significantly induced collagen synthesis and inhibited collagenase activity in ERM-CZ100-stimulated HDF cells. Further study demonstrated that DPHC remarkably reduced the expression of human matrix metalloproteinases through regulation of nuclear factor kappa B, activator protein 1, and mitogen-activated protein kinases signaling pathways in ERM-CZ100-stimulated HDF cells. This study suggested that DPHC is a potential candidate to protect skins against PM-induced damage, and it could be used as an ingredient in pharmaceutical and cosmeceutical industries.

Based on data from prospectuses of GEM listed companies in China, the signaling effect of pre-listing dividend distribution policy is investigated. If the dividend signaling effect exists in Chinese IPO markets, there is likely a negative relationship between pre-listing dividends and IPO underpricing, also a positive relationship between pre-listing dividends and IPO stock price performance. The results of the empirical analysis show that there is a reasonable correlation between pre-listing cash dividend distribution and IPO pricing and stock price performance, and different information connotations are exhibited in the primary and secondary markets. Specifically, companies that have distributed cash dividends in the three years prior to the IPO, especially those that have distributed steadily for three consecutive years, have a significantly lower IPO price suppression rate than non-distributing companies, while the cumulative IPO excess return rate is significantly higher than that of non-distributing companies. Moreover, pre-listing dividend distribution is significantly and positively correlated with the cumulative excess return at 60, 120, and 240 days after IPO, that is, companies that distribute dividends steadily before IPO have better IPO stock price performance. The study also finds that companies that distribute dividends unexpectedly before going public have more severe price depression, but their cumulative excess returns at 60, 120, and 240 days after going public are still not significantly different from that of other companies, even when higher issue depression is included. This suggests that pre-listing dividends help mitigate information asymmetry between issuers and public investors, increase the value of companies in the primary market and reduce IPO price suppression. Similarly, companies that pay stable dividends before going public are more recognized by the market, increasing the value of the company in the secondary market and increasing the cumulative IPO excess return. However, pre-listing surprise dividends do not have a signaling effect and fail to be favored by secondary market investors. By reviewing both classic and recent literature, we consider that our many-sided discussions on the signaling hypothesis and IPO stock price performance contribute to related future research in this field.

High mobility group box 1 (HMGB1) plays a crucial mediator in the pathogenesis of many inflammatory diseases. We recently proposed that heme oxygenase-1 (HO-1) negatively regulates HMGB1 in inflammatory conditions. We investigated whether ethanol extract of Inula helenium L. (EIH) activates p38 MAPK/Nrf2/HO-1 pathways in RAW264.7 cells and reduces inflammation in CLP-induced septic mice. EIH induced expression of HO-1 protein in a time- and concentration-dependent manner. EIH significantly diminished HO-1 expression in siNrf2 RNA-transfected cells. As expected, the inhibited expression of iNOS/NO, COX-2/PGE2, HMGB1 release by EIH in LPS-activated RAW264.7 cells was significantly reversed by siHO-1RNA transfection. Furthermore, EIH not only inhibited NF-jB luciferase activity, phosphorylation of IjBa in LPS-activated cells but also significantly suppressed expression of adhesion molecules (ICAM-1 and VCAM-1) in TNF-a activated human umbilical vein endothelial cells. The induction of HO-1 by EIH was inhibited by SB203580 but not by SP600125, PD98059, nor LY294002. Most importantly, administration of EIH significantly reduced not only increase in blood HMGB1, ALT, AST, BUN, creatinine levels but also decrease macrophage infiltrate in the liver of septic mice, which were reversed by ZnPPIX, a HO-1 inhibitor. We concluded that EIH has anti-inflammatory effect via the induction of p38 MAPK-dependent HO-1 signaling pathway.

Emphysema, a pathological component of chronic obstructive pulmonary disease, causes irreversible damage to the lung. Previous studies have shown that Slit plays essential roles in cell proliferation, angiogenesis, and organ development. In this study, we evaluated the effect of Slit2 on the proliferation and migration of mouse lung epithelial cells and its role in regeneration in an emphysema lung mouse model. Here, we have shown that Slit2/Robo signaling contributes to the regeneration of lungs damaged by emphysema. Mouse epithelial lung cells treated with Slit2 exhibited increased proliferation and migration in vitro. Our results also showed that Slit2 administration improved alveolar regeneration in the emphysema mouse model in vivo. Furthermore, Slit2/Robo signaling increased the phosphorylation of ERK and Akt, which was mediated by Ras activity. These Slit2-mediated cellular signaling processes may be involved in the proliferation and migration of mouse lung epithelial cells and are also associated with the potential mechanism of lung regeneration. Our findings suggest that Slit2 administration may be beneficial for alveolar regeneration in lungs damaged by emphysema.

Alopecia has emerged as one of the biggest interests in modern society. Many studies have focused on the treatment of alopecia, such as transplantation of hair follicles or inhibition of the androgen pathway. Hair growth is achieved through proper proliferation of the components such as keratinocytes and dermal papilla cells (DPCs), movement, and interaction between the two cells. The present study examined the effect of the hedgehog (Hh) signaling pathway, which is an important and fundamental signal in the cell, on the morphology and the viability of human keratinocytes and DPCs. Upregulation of Hh signaling caused a morphological change and an increase in epithelium-mesenchymal transition-related gene expression but reduced the viability of keratinocytes, while the alteration of Hh signaling did not cause any change in DPCs. The results show the possibility that the regulation of Hh signaling can be applied for the treatment of alopecia.

In many radio communication environments, there is a special component, called inter-symbol interference (ISI), mused by multipath time delay of signal and ISI components impose limitation of the data transmission rate. In this paper, we consider signaling pulse shapes, called partial response signaling (PRS), for minimizing the effect of ISI and show the improvement of performance by applying one of the partial-response signaling (PRS) pulses to two types of receiver system under dependent noise environments through the Monte-Carlo computer simulations.

Purpose - This study attempts to provide a new theoretical perspective on the quality signaling and its impact on a market under information asymmetry, focusing on how the accuracy and the cost of quality signaling affect sellers’ and buyers’ profit, suggesting appropriate designs of quality signaling methods which mitigates information asymmetry. Design/methodology/approach - In order to examine the effect of quality signaling on strategic interactions within the market, we establish an analytic model where market outcomes are determined by seller’s quality claim and price, and buyers are risk-neutral. By investigating this analytic model through relevant game trees, we find the subgame perfect Nash equilibria of the market and predict related market outcomes based on sellers’ quality signaling strategy. Findings - Our analytic model shows counterintuitive results that seller profit will be the lowest with inaccurate quality signaling and the highest with no quality signaling, mostly due to the certification cost. Consequently, sellers should proceed with caution if the quality signaling is less than accurate, as it may backfire. We believe that this is due to the fact that the inaccuracy of quality signaling causes some confusion and uncertainty in both sellers and buyers’ decision to maximize profit, making it hard for sellers to predict buyers’ behavior. Research implications or Originality - Although the sources and types of quality signaling errors have been investigated in the literature, there has not been satisfactory understanding regarding how inaccuracy of quality certification affects specific market outcomes. We expect that our theoretical model would provide important implications on how to utilize quality signaling to solve adverse selection issues in markets under information asymmetry.

Aging is characterized by the progressive loss of physiological integrity, leading to impaired tissue function and increased vulnerability to chronic diseases. Although the Hedgehog (Hh) signaling pathway is well established as a key regulator of embryonic development and tumorigenesis, emerging evidence suggests it also plays vital roles in adult tissue maintenance, regeneration and immune modulation?processes that are intimately linked to aging. Here we synthesize recent findings demonstrating that the controlled activation of Hh signaling across diverse tissues, including the brain, liver, heart, lung, bone, skin and adipose tissue, can counteract hallmark features of aging such as stem cell exhaustion, mitochondrial dysfunction and chronic inflammation. In preclinical models, Hh pathway modulation enhances tissue regeneration, supports progenitor cell function and suppresses senescence-associated secretory phenotypes. Promising therapeutic strategies?ranging from gene delivery to pharmacological agonists?have shown efficacy in mitigating age-related decline, though challenges remain regarding tissue specificity, long-term safety and tumorigenic risk. By integrating insights from developmental biology, regenerative medicine and geroscience, this Review positions Hh signaling as a compelling target for anti-aging interventions aimed at preserving organ function and extending healthspan.

G protein-coupled estrogen receptor (GPER) is known to play an important role in hormone-associated cancers. G-1, a novel synthetic GPER agonist, has been reported to exhibit anti-carcinogenic properties. However, the chemotherapeutic mechanism of GPER is yet unclear. Here, we evaluated GPER expression in human gastric cancer tissues and cells. We found that G-1 treatment attenuates GPER expression in gastric cancer. GPER expression increased G-1-induced antitumor effects in mouse xenograft model. We analyzed the effects of knockdown/overexpression of GPER on G-1-induced cell death in cancer cells. Increased GPER expression in human gastric cancer cells increased G-1-induced cell death via increased levels of cleaved caspase-3, -9, and cleaved poly ADP-ribose polymerase. Interestingly, during G-1-induced cell death, GPER mRNA and protein expression was attenuated and associated with ER stress-induced expression of PERK, ATF-4, GRP-78, and CHOP. Furthermore, PERK-dependent induction of ER stress activation increased G-1-induced cell death, whereas PERK silencing decreased cell death and increased drug sensitivity. Taken together, the data suggest that the induction of ER stress via GPER expression may increase G-1-induced cell death in gastric cancer cells. These results may contribute to a new paradigm shift in gastric cancer therapy.