Search

Objective To investigate whether induction of heme oxygenase-1 (HO-1) can reduce skeletal muscle atrophy in mice by inhibiting the activation of NLRP3 inflammasome. Methods Thirty-two 8-week-old male C57BL/6 mice were randomly divided into normal group, model group (the model of lower limb muscular atrophy was established by tail suspension), heme chloride group (HO-1 expression was induced by intraperitoneal injection of hemin in the model mice), and zinc protoporphyrin group (on the basis of hemin chloride group, ZnPP was injected intraperitoneally to antagonize HO-1 expression), with 8 mice in each group. Another 8 mice at the same age were injected with lentivirus into tibialis anterior muscle and the model of lower limb muscle atrophy was established simultaneously, with the left side as lentivirus intervention subgroup (injection of lentiviral vector of NLRP3 RNAi to inhibit the expression of NLRP3), and the right side as lentivirus control subgroup (injection of blank lentiviral vector). The changes of muscle volume were observed by HE staining and muscle/body weight ratio. The protein levels of NLRP3, ASC and Caspase-1 in the tibialis anterior muscle were determined by Western blotting. The levels of IL-1β and IL-18 and oxidative stress molecules in the muscle tissues were determined by ELISA. Results The typical mouse model of lower extremity muscular atrophy was successfully established by tail suspension. HO-1 induction resulted in significantly reduced muscular atrophy and decreased expression of NLRP3 inflammasome related proteins ASC and Caspase-1 in the heme chloride group when compared with the model group (P < 0.05). There were no significant differences in the protein levels of above 2 molecules between the zinc protoporphyrin group and the model group. Knockdown of NLRP3 by lentiviral vector led to significantly reduced muscle atrophy, decreased expression of NLRP3 inflammasome related proteins (P < 0.05), and lower levels of downstream proteins IL-1 β and IL-18 (P < 0.05) when compared with the lentivirus control subgroup; The oxidative stress of muscle tissue was alleviated (P < 0.05). Conclusion Induction of HO-1 can reduce skeletal muscle atrophy in tail suspension mice by inhibiting the activation of NLRP3 inflammasome.

Substantial evidence from experimental studies has shown that mating motivation increases men’s financial risk-taking behaviors. The present study proposed a new moderator, men’s past relationship experience, for this well-accepted link between mating motivation and financial risk-taking tendency. Heterosexual young men were randomly assigned to the mating condition and control condition, and they completed a set of financial risk-taking tasks and reported their past relationship experience. A significant main effect of mating motivation and a significant interaction effect between experimental conditions (mating group and control group) and relationship experience emerged, suggesting that mating motivation increased financial risk-taking tendency only among men who have never been committed in a romantic relationship, rather than those who have had such experience. This moderating effect was replicated in two experiments. The present study contributed to the understanding of individual differences in the relationship between mating motivation and male financial risk-taking. The present findings also have important implications for financial industry and gambling companies to better target clients and advertise their high-risk products.

The ending effect describes the phenomenon that at the end of a series of repeated risky decision-making tasks, participants become more likely to engage in risk-taking behavior. Past research has suggested that the ending effect might be caused by a motivational shift induced by changes in time perception. Previous studies mainly tested this phenomenon in a binary decision-making setting (e.g., a decision-making task usually includes two alternatives). However, none of these prior studies included safe options and risky options that differed in risk levels. To address this knowledge gap, the present study replicated the ending effect in a repeated decision-making task that included both a safe option and risky options that differed in risk levels (N = 104). We found that at the end of the decision-making task, participants became more likely to engage in risk-taking and to favor the option with the highest risk. Further, we found that the investment likelihood and investment amount of high-risk options both increased significantly at the ending. In addition, a shift in favoring the safe option emerged in the noninformed condition at the end. We also found that the emotional motivation in the last round could predict the increased preference for high-risk at the ending. This study extended previous findings on the ending effect by adopting a more complex decision-making scenario and, more broadly, helped further our understanding of the psychological consequences of perceived endings.

Healthcare workers play a vital role in the fight against COVID-19. Based on Terror Management Theory (TMT), the present research examined whether a close relationships defense mechanism reduces anxiety among healthcare workers (N = 729) in China. Our results suggest that this defense mechanism, as indexed by relationship satisfaction, serves as an effective terror management source after exposure to reminders of death (MS; mortality salience). These findings extend TMT by identifying two moderating variables: vulnerability and social support. In a low objective vulnerability group, healthcare workers who subjectively believed themselves as less vulnerable to COVID-19 showed a stronger defense mechanism after a MS manipulation as compared to those who felt more vulnerable. Further, healthcare workers with higher levels of social support reported more relationship satisfaction. These findings have practical implications for guiding healthcare workers on how to buffer death-related anxiety and maintain their mental health in the fight against COVID-19.

Under the impact of COVID-19, the status and mechanisms of post-traumatic growth among medical workers facing challenges related to family-work conflict are of great concern. In view of the complex relationship between family-work conflict and post-traumatic growth, the present study sought to explore the specific relationships between family-work conflict and post-traumatic growth as well as the specific roles of positive psychological capital, perceived social support, and suppression. We recruited 1,347 participants. The results revealed that positive psychological capital and perceived social support played mediating roles, while suppression strategies moderated the mediating effect. Compared with the low suppression group, the negative impact of family-work conflict on positive psychological capital and perceived social support was reduced in the high suppression group. Thus, a higher level of suppression was more conducive to post-traumatic growth. The current study enriches and expands the findings of previous studies in theory and provides practical ways to promote post-traumatic growth in medical workers.

The ending effect describes the phenomenon that individuals are more risk-taking during the final round of a series of risky decision tasks. Previous research suggests that the ending effect might be caused by a motivational shift induced by changes in time perception. However, none of the existing research directly tested the motivational state immediately before the last round of a series of risky decision tasks. To fill in this gap of knowledge, the present study tested whether this motivational shift indeed occurs immediately before the last round. All participants worked on 11 rounds of risky decision tasks, half of them knew that the decision tasks included 11 rounds, whereas the other half did not know. Before the last round of the risky decision tasks, all participants completed a visual reaction time task. It was found that, compared with participants who were not aware of the impending ending, those who knew they were approaching the last round responded to peripherally located character strings appearing immediately after gain-related words slower than those appearing after loss-related words, suggesting that perceived endings lead participants to be more motivated toward gaining rewards. This work provides critical evidence which supports the motivational account of the ending effect proposed in previous research. Such a finding would represent a next step in unpacking the psychological consequences of perceived endings in everyday life.

Past studies suggested that sex ratio influences individuals’ economic behaviors; however, the underlying mechanism of this effect remains unclear. In the current work, we examined how sex ratio influenced women’s preference for relative gain over greater absolute gain in the context of games involving resource allocation between oneself and another woman; the role of intrasexual competition in this process was also explored. By experimentally manipulating women’s perceptions of local sex ratio, the present study found that women primed with a female-biased sex ratio (i.e., an excess of women) showed higher levels of intrasexual competition. Exposure to the cue of a scarcity of men also led women to care more about their relative gain compared with absolute gain. The effect of sex ratio on shifts of women’s preference between relative gain and absolute gain was mediated by the strength of women’s competitive attitude toward same-sex others. These findings suggest that, by altering the intensity of female–female competition, sex ratio may have a pronounced effect on women’ economic-related decisions.