Impact of visitation restrictions on the mental health of family caregivers during the COVID-19 pandemic: A mixed methods study.

AIM: To examine the mental health conditions of family caregivers residing away from their loved ones who experienced visitation restrictions during the coronavirus disease 2019 pandemic. DESIGN: A mixed-methods design applying the Kessler Scale-10 for the quantitative measurement of psychological distress and an open-ended question for qualitative analysis. METHODS: The participants were recruited from care facilities between February and September 2021. This cross-sectional study included 197 family caregivers who were utilizing formal residential care services for their loved ones. Using thematic analyses, open-ended responses regarding the impact of visitation restrictions were coded. These themes were then examined to determine thematic patterns across caregiver characteristics. RESULTS: Thirteen themes were identified regarding the impact of visitation restrictions. Many participants reported primary harmful effects as follows: 'inability to confirm the type of care and lifestyle assistance provided to an older relative' and 'difficulty communicating with an older relative because of the inability to converse face-to-face'. Younger age, being employed, poor sleep, poor relationship quality with the care recipient and experiencing harmful effects from the visitation restrictions were associated with psychological distress. CONCLUSION: Our findings suggest that to maintain positive mental health after a care transition, it is important for family caregivers to take part in the care of their loved ones and ensure information sharing between the care recipient's family and institution. IMPACT: These findings suggest that both residents and family caregivers living outside facilities may feel distressed due to separation. Therefore, institutional care staff needs to consider how to adjust facility procedures or communication with family caregivers. PATIENT OR PUBLIC CONTRIBUTION: The comments obtained from the participants in this survey helped to shape the study design and are expected to contribute to the further development of quality facility care.

Predictive Factors of Negative Spillover From Caregiving to Employment Among Japanese Family Caregivers With Older Relatives in a Care Facility.

This cross-sectional study included 211 employed family caregivers with older relatives living in care facilities in Japan. Using multiple linear regression analysis, we examined the caregiving context after institutionalization of an older family member. Specifically, we examined predictors of negative spillover from caregiving to employment among family caregivers. The outcome was the extent of negative spillover. Primary predictors included caregiver characteristics and postinstitutionalization caregiving contexts such as caregiving tasks and dissatisfaction with institutional care services. Among all caregivers, 134 (63.5%) were female, and approximately half of all caregivers reported satisfaction with institutional care services. We found that dissatisfaction with institutional care services and being a female each had a main effect on greater negative spillover. However, they did not have any interacting effect on negative spillover after the institutionalization. Negative spillover did not terminate when older family members were institutionalized. Higher satisfaction with institutional care may reduce negative spillover.

Predictors of Effort-Reward Imbalance Among Employees Providing Three Types of Long-Term Care Services in Japan: Implications for Employee Well-Being.

The purpose of this study was to identify predictive factors of effort-reward imbalance (ERI) among employees in multiple long-term care settings in Japan. This cross-sectional study by convenience sampling included 944 participants providing three types of long-term care: home-based (n = 201), community-based (n = 128), and institutional (n = 615). Multiple logistic regression analysis was used to identify factors associated with self-reported ERI. Low job satisfaction, being a care manager, holding a position of department head, working long hours, and having family-related stress were the common factors associated with ERI in employees across all three types of long-term care setting. Long-term care providers should consider the needs of care recipients and their family, as well as the needs of care employees, maximizing rewards so that turnover can be reduced and the diversity of individual work-family needs can be accommodated across multiple forms of long-term care settings.

Exercise Self-Efficacy as a Mediator between Goal-Setting and Physical Activity: Developing the Workplace as a Setting for Promoting Physical Activity.

BACKGROUND: Physical activity (PA) is ranked as a leading health indicator and the workplace is a key setting to promote PA. The purpose of this study was to examine how goal-setting and exercise self-efficacy (SE) during a health promotion program influenced PA level among Japanese workers. METHODS: Using a cross-sectional study design, we surveyed 281 employees. The short version of the International Physical Activity Questionnaire was used to assess PA level. Exercise SE was assessed using a partially modified version of Oka's exercise SE scale. Personal goals were assessed as the total numbers of "yes" responses to five items regarding "details of personal goals to perform PA". A mediational model was used to examine whether exercise SE mediates between the number of personal goals and PA level. RESULTS: The mean age of the participants was 46.3 years, 76.2% were men, and the most common occupational category was software engineer (30.6%). The average PA level per week exceeded the recommended level in 127 participants (45.2%). One hundred and eighty-four participants (65.5%) set some form of concrete personal goal to perform PA. The relationship between the number of personal goals and PA level was mediated by exercise SE. CONCLUSION: Our study showed that exercise SE mediates goal-setting and increases PA. The results suggest that the components of PA promotion programs should be tailored to enhance participants' confidence in performing PA.

Communication, support and psychosocial work environment affecting psychological distress among working women aged 20 to 39 years in Japan.

When compared with their older counterparts, younger women are more likely to have depressive symptoms because they more often experience interrupted work history and a heavy childrearing burden. The purposes of the present study were 1) to investigate the possible association of psychosocial work environment with psychological distress and 2) to examine the way by which communication and support in the workplace affect to psychological distress among young women. We studied 198 women aged 20 to 39 yr in a cross-sectional study. The Kessler Scale-10 (K10 Scale) was used to examine psychological distress. In employees who experienced interpersonal conflict, those who had little or no conversations with their supervisor and/or co-workers had a significantly increased risk of psychological distress (OR, 4.2), and those who received little or no support from their supervisor and/or co-workers had a significantly increased risk of psychological distress (OR, 3.8) compared to those who had more frequent communication and received more support. Harmonious communication in the workplace can help prevent psychological distress among employees, which in turn may enable them to be satisfied with their work.

The Impact of Multiple Roles on Psychological Distress among Japanese Workers.

BACKGROUND: There has been considerable interest in Japanese society in the problem of work-related stress leading to depressive symptoms, and an increasing number of primary houseworkers maintain paid employment. The purpose of this study was to examine the differential impact of multiple roles associated with psychological distress among Japanese workers. METHODS: We studied 722 men and women aged 18-83 years in a cross-sectional study. The K10 questionnaire was used to examine psychological distress. RESULTS: The proportion of participants with psychological distress was higher in women (17.8%) compared with men (11.5%). Having three roles significantly decreased the risk of psychological distress [women: odds ratio (OR), 0.37-fold; men: OR, 0.41] compared with only one role. In working married women, there was significantly less psychological distress (OR, 0.27), and those with childrearing or caregiving responsibilities for elderly parents had significantly less psychological distress (OR, 0.38) than those with only an employment role. Similarly, working married men who had childrearing or caregiving responsibilities for elderly parents had significantly less psychological distress (OR, 0.41) than those who had only an employment role. CONCLUSION: The present study demonstrated that participants who had only an employment role had an increased risk of psychological distress. The degree of psychological distress was not determined solely by the number of roles. It is important to have balance between work and family life to reduce role conflict and/or role submersion, which in turn may reduce the risk of psychological distress.

Work-related Stress, Caregiver Role, and Depressive Symptoms among Japanese Workers.

BACKGROUND: In Japan, more than 60% of employees are reported to suffer from anxiety and stress. Consequently, Japanese society has begun to address such important issues as psychogenic disability and job-related suicide. Furthermore, given the aging of society and the surge in the number of elderly people requiring care, it is necessary to adequately and proactively support employees who care for their elderly relatives. The purpose of the present study was to investigate caregiver burden in caring for elderly relatives and work-related stress factors associated with mental health among employees. METHODS: We studied 722 men and women aged 18-83 years in a cross-sectional study. The K10 questionnaire was used to examine mental health status. RESULTS: The proportion of participants with a high K10 score was 15% (n = 106). Having little conversation with their supervisor and/or coworkers significantly increased the risk of depression [odds ratio (OR) 1.8], as did high job overload (OR 2.7) and job dissatisfaction (OR 3.8), compared with employees who frequently conversed with their supervisor and/or coworkers. Caring for elderly relatives as a prominent characteristic of an employee was a significant risk factor for depression (OR 2.1). CONCLUSION: The present study demonstrated that employees who were caring for elderly relatives were significantly associated with an increased risk of depression. To prevent depressive disorders, it may be important to focus on reducing the work-caregiving role conflict, as well as enhancing employees' job control and better rewarding their efforts in the workplace.

Caregiver burden mediates between caregiver's mental health condition and elder's behavioral problems among Japanese family caregivers.

OBJECTIVES: In Japan, the prevalence of depression has been reported to occur among 1 in 4 family caregivers. The purpose of this study was to investigate the self-rated burden associated with mental health conditions among caregivers. METHODS: We studied 95 caregivers aged 38-87 years in a cross-sectional study. The General Health Questionnaire (GHQ-12) score of 4 or more was defined as poor mental health. RESULTS: The proportion of caregivers with poor mental health was 24%. Caregivers with a high GHQ-12 score had the number of caregiver burdens increased by 2.5-fold compared to those with a low GHQ-12 score (p = 0.001). The proportion of caregivers with a high GHQ-12 score was significantly higher with an increasing number of behavioral problems among care recipients (p = 0.003). A mediational model was used to identify the underlying mechanism of the relationship between the number of behavioral problems and poor mental health in caregivers. Consequently, we found that mental health conditions in caregivers were associated with both the number of caregiver burdens and behavioral problems among care recipients. CONCLUSIONS: It is vital to provide support not only to the caregivers but also to their elderly relatives, paying particular attention to early identification of poor mental health in caregivers so as to administer effective interventions, and to offer useful advice concerning how to deal with behavioral problems.

Macrophage migration inhibitory factor is essential for eosinophil recruitment in allergen-induced skin inflammation.

Macrophage migration inhibitory factor (MIF) is a pluripotent cytokine that has an essential role in the pathophysiology of experimental allergic inflammation. Recent findings suggest that MIF is involved in several allergic disorders, including atopic dermatitis (AD). In this study, the role of MIF in allergic skin inflammation was examined using a murine model of AD elicited by epicutaneous sensitization with ovalbumin (OVA). We observed the number of skin-infiltrating eosinophils to significantly increase in OVA-sensitized MIF transgenic (Tg) mice compared with their wild-type (WT) littermates. On the other hand, eosinophils were virtually absent from the skin of MIF knockout (KO) mice and failed to infiltrate their skin after repeated epicutaneous sensitization with OVA. The mRNA expression levels of eotaxin and IL-5 were significantly increased in OVA-sensitized skin sites of MIF Tg mice, but were significantly decreased in MIF KO mice in comparison with the levels in WT littermates. Eotaxin expression was induced by IL-4 stimulation in fibroblasts in MIF Tg mice, but not in MIF KO mice. These findings indicate that MIF can induce eosinophil accumulation in the skin. Therefore, the targeted inhibition of MIF might be a promising new therapeutic strategy for allergic skin diseases.

Protective effects of platinum nanoparticles against UV-light-induced epidermal inflammation.

Intracellular reactive oxygen species (ROS) and apoptosis play important roles in the ultraviolet (UV)-induced inflammatory responses in the skin. Metal nanoparticles have been developed to increase the catalytic activity of metals, which is because of the large surface area of smaller particles. Platinum nanoparticles (nano-Pt) protected by poly acrylic acid were manufactured by reduction with ethanol. A marked increase in ROS production was observed in UV-treated HaCaT keratinocytes cell lines, while a decrease in ROS production was observed in nano-Pt-treated cells. Pretreatment of the cells with nano-Pt also caused a significant inhibition of UVB- and UVC-induced apoptosis. Furthermore, we found that mice treated with nano-Pt gel prior to UV irradiation showed significant inhibition of UVB-induced inflammation and UVA-induced photoallergy compared to UV-irradiated control mice. These results suggest that nano-Pt effectively protects against UV-induced inflammation by decreasing ROS production and inhibiting apoptosis in keratinocytes.

Deficient deletion of apoptotic cells by macrophage migration inhibitory factor (MIF) overexpression accelerates photocarcinogenesis.

Chronic ultraviolet (UV) exposure can increase the occurrence of p53 mutations, thus leading to a dysregulation of apoptosis and the initiation of skin cancer. Therefore, it is extremely important that apoptosis is induced quickly after UV irradiation, without any dysregulation. Recent studies have suggested a potentially broader role for macrophage migration inhibitory factor (MIF) in growth regulation via its ability to antagonize p53-mediated gene activation and apoptosis. To further elucidate the possible role of MIF in photocarcinogenesis, the acute and chronic UVB effect in the skin was examined using macrophage migration inhibitory factor transgenic (MIF Tg) and wild-type (WT) mice. The MIF Tg mice exposed to chronic UVB irradiation began to develop skin tumors after approximately 14 weeks, whereas the WT mice began to develop tumors after 18 weeks. A higher incidence of tumors was observed in the MIF Tg in comparison with the WT mice after chronic UVB irradiation. Next, we clarified whether the acceleration of photo-induced carcinogenesis in the MIF Tg mice was mediated by the inhibition of apoptosis There were fewer sunburned cells in the epidermis of the MIF Tg mice than the WT mice after acute UVB exposure. The epidermis derived from the MIF Tg mice exhibited substantially decreased levels of p53, bax and p21 after UVB exposure in comparison with the WT mice. Collectively, these findings suggest that chronic UVB exposure enhances MIF production, which may inhibit the p53-dependent apoptotic processes and thereby induce photocarcinogenesis in the skin.

Macrophage migration inhibitory factor ameliorates UV-induced photokeratitis in mice.

Acute ultraviolet (UV) exposure causes photokeratitis, and induces apoptosis in corneal cells of the eye. Macrophage migration inhibitory factor (MIF) was originally identified as a lymphokine. Today, MIF is considered as an integral component of the host antimicrobial alarm system and stress response that promotes the proinflammatory functions of immune cells. Also, MIF is considered to contribute the wound healing process. The aim of the present study is to determine the effects of MIF expression on UV irradiated corneal damage. MIF transgenic (MIF-Tg), wild type (WT), and MIF deficient (MIF KO) mice were UVB-irradiated of 400mJ/cm2 to induce acute UV-photokeratitis. MIF Tg mice constitutively produce high levels of MIF. Morphological changes were most severe in MIF KO mice, and WT and MIF Tg mice were following. Corneal basement membrane of MIF-Tg was well preserved. Prominent higher level of MIF was observed in MIF-Tg than WT after UVB irradiation in cornea. TUNEL staining showed a significantly smaller number of TUNEL positive nuclei in MIF-Tgm (6.2+/-4.3 cells/section, p<0.01 compared with WT) than WT (30.7+/-9.1) and MIF KO mice (32.1+/-12.7) 24h after UV exposure. The number of c-Jun positive nuclei was significantly higher in MIF Tg (p<0.01) than in WT and MIF KO mice. Serial observation revealed that BrdU incorporation was significantly upregulated in MIF Tg (p<0.01), but downregulated in MIF KO (p<0.01) than WT mice. MIF expression may thus be related to the amelioration of UVB-caused corneal injury, and this association was attributable to the upregulation of cell proliferation after acute UV-induced corneal damage, which involves the c-Jun dependent pathway. In conclusion, UV-damaged cornea is recoverable without MIF, however it takes longer time than normal condition. Cornea is less damaged and can make a quick recovery when ocular tissue is enough supplied with MIF.

Interleukin-1beta and macrophage migration inhibitory factor (MIF) in dermal fibroblasts mediate UVA-induced matrix metalloproteinase-1 expression.

BACKGROUND: Exposure to solar UV radiation is the main environmental factor that causes premature aging of the skin. Matrix metalloproteinases (MMP)-1 is a member of the MMP family and degrades types I and III collagens, which are the major structural components of the dermis. OBJECTIVE: We evaluated the involvement IL-1beta and macrophage migration inhibitory factor (MIF) in MMP-1 expression under ultraviolet A (UVA) irradiation. METHODS: IL-1beta and MIF in MMP-1 expression in cultured human dermal fibroblasts and the UVA effects on MMPs production using IL-1alpha/beta-deficient mice were analyzed. Furthermore, fibroblasts derived from MIF-deficient mice were used to analyze the effect of IL-1beta-induced MMPs production. RESULTS: IL-1beta-enhanced MIF expression and induced MMP-1 in cultured human dermal fibroblasts. IL-1beta-induced MMP-1 expression is inhibited by neutralizing anti-MIF antibody. Dermal fibroblasts of IL-1alpha/beta-deficient mice produced significantly decreased levels of MMPs compared to wild-type mice after UVA irradiation. Furthermore, fibroblasts of MIF-deficient mice were much less sensitive to IL-1beta-induced MMPs production. On the contrary, IL-1beta produced significantly decreased levels of MMPs in MIF-deficient mice fibroblasts. The up-regulation of MMP-1 mRNA by IL-1beta stimulation was found to be inhibited by a p38 inhibitor and a JNK inhibitor. In contrast, the MEK inhibitor and inhibitor were found to have little effect on expression of MMP-1 mRNA. CONCLUSIONS: IL-1beta is involved in the up-regulation of UVA-induced MMP-1 in dermal fibroblasts, and IL-1beta and MIF cytokine network induce MMP-1 and contribute to the loss of interstitial collagen in skin photoaging.

Polymorphisms in the muscarinic receptor 1 gene confer susceptibility to asthma in Japanese subjects.

RATIONALE: The human cholinergic receptor muscarinic-1 (CHRM1) is widely distributed in the lungs. In patients with asthma, CHRM1 may be involved in airway constriction, airway epithelial cell proliferation, and airway inflammation. The CHRM1 gene is located on chromosome 11q13, which is one of the candidate loci for asthma and atopy. OBJECTIVES: To determine the role of the CHRM1 gene polymorphisms in asthma. METHODS: We studied nine single-nucleotide polymorphisms (-18379G > A, -9697C > T, -6965T > C, -4953A > G, +267A > C, +1353C > T, +3970C > G, +5418C > G, and +5455G > T) in a case-control study using 326 patients with asthma and 333 healthy control subjects. We also examined functional consequences of the -9697C > T and -4953A > G polymorphisms at the regulatory region using an mRNA reporter assay. MEASUREMENTS AND MAIN RESULTS: Two common single-nucleotide polymorphisms (-9697C > T and -4953A > G) were associated with asthma. The odds ratio for the TT homozygotes at the -9697C > T polymorphism was 0.29 compared with the CC homozygotes (95% confidence interval, 0.12-0.73; p = 0.008), and the odds ratio for the GG homozygotes at the -4953A > G polymorphism was 1.86 compared with the AA homozygotes (95% confidence interval, 1.04-3.34; p = 0.038). Haplotype analysis showed that the -9697T/-6965T/-4953A haplotype was associated with a lower risk of asthma (p = 0.00055) and the -9697C/-6965T/-4953G haplotype was associated with an increased risk of asthma (p = 0.020). The -9697T/-4953A haplotype was also associated with lower luciferase activity in vitro compared with the -9697C/-4953G haplotype. CONCLUSIONS: This study, together with an in vitro functional study, suggests that the CHRM1 gene is an important susceptibility locus for asthma on chromosome11q13.

Presence of circulating CCR10+ T cells and elevated serum CTACK/CCL27 in the early stage of mycosis fungoides.

PURPOSE: Mycosis fungoides (MF), a common type of cutaneous T cell lymphoma with an indolent clinical course, has the characteristic that malignant T cell clones are recruited into the skin from the early disease stages. The mechanisms of recruitment have been suggested from our knowledge of various chemokine-chemokine receptor interactions. Recently, CCR10 and CTACK/CCL27 were proposed to play a role in the recruitment of other types of cutaneous T cell lymphoma. We examined the expression of CCR10 in peripheral blood and serum CTACK/CCL27 levels in patients with MF. EXPERIMENTAL DESIGN: Eighteen patients with MF, six patients with atopic dermatitis, and nine healthy volunteers were enrolled in our investigation. We investigated the differences in CCR10+ CD4+ expression in peripheral blood mononuclear cells by flow cytometry. Serum CTACK/CCL27 levels were determined using a CTACK/CCL27 ELISA assay kit. RESULTS: The number of circulating CCR10+ CD4+ cells was significantly higher in MF peripheral blood than in controls, even during the early stages. In lesional MF skin, infiltrating tumor cells also showed extensive expression of CCR10. The serum level of CTACK/CCL27 was higher in patients with MF than normal controls, but no statistical difference was found compared with atopic dermatitis patients. CONCLUSIONS: CCR10-CTACK/CCL27 interactions between circulating T cells and keratinocytes would seem to play an important role in the pathophysiology of MF from the early disease stages.

Increase in macrophage migration inhibitory factor levels in lacrimal fluid of patients with severe atopic dermatitis.

BACKGROUND AND AIMS OF THE STUDY: Atopic dermatitis is a chronic inflammatory skin disorder that often involves some ophthalmic features. Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine that is associated with the generation of cell-mediated immune responses. Although serum MIF levels may be elevated in severe atopic dermatitis, the quantity of MIF in regional ocular fluid remains unknown. We measured MIF levels in tears (lacrimal fluid) of patients with atopic dermatitis. PATIENTS AND METHODS: Tear samples were collected from 16 patients with atopic dermatitis, 10 patients with allergic conjunctivitis, and 15 healthy control subjects. The clinical severity of atopic dermatitis was evaluated according to the Scoring Atopic Dermatitis (SCORAD) index. The index was calculated by summing the following scores: extent criteria, intensity criteria, and subjective symptoms. Macrophage migration inhibitory factor levels were determined by a human MIF enzyme-linked immunosorbent assay. All comparisons were two-tailed, and P values <0.01 were considered as statistically significant. RESULTS: The mean MIF concentration in lacrimal fluid collected from healthy control subjects was 0.69+/-0.2 ng/ml. The mean tear MIF levels were 17.87+/-6.3 ng/ml in moderate-to-severe atopic dermatitis (SCORAD> or =15, P=0.002), 0.93+/-0.08 ng/ml in mild atopic dermatitis (SCORAD<15), and 2.76+/-0.86 ng/ml in allergic conjunctivitis (P=0.008). CONCLUSIONS: A proinflammatory cytokine MIF level was elevated in tears as well as serum in cases of severe atopic dermatitis. These results suggest that MIF may play an important role in the induction or enhancement of ophthalmic features related to severe atopic dermatitis.

Tissue regeneration using macrophage migration inhibitory factor-impregnated gelatin microbeads in cutaneous wounds.

Migration inhibitory factor (MIF) responds to tissue damage and regulates inflammatory and immunological processes. To elucidate the function of MIF in cutaneous wound healing, we analyzed MIF knockout (KO) mice. After the excision of wounds from the dorsal skin of MIF KO and wild-type (WT) mice, healing was significantly delayed in MIF KO mice compared to WT mice. Lipopolysaccharide treatment significantly increased [(3)H]thymidine uptake in WT mouse fibroblasts compared to MIF KO mouse fibroblasts. Furthermore, there was a significant reduction in fibroblast and keratinocyte migration observed in MIF KO mice after 1-oleoyl-2-lysophosphatidic acid treatment. We subsequently examined whether MIF-impregnated gelatin slow-release microbeads could accelerate skin wound healing. Injection of more than 1.5 microg/500 microl of MIF-impregnated gelatin microbeads around a wound edge accelerated wound healing compared to a single MIF injection without the use of microbeads. MIF-impregnated gelatin microbeads also accelerated skin wound healing in C57BL/6 mice and diabetic db/db mice. Furthermore, incorporating MIF-impregnated gelatin microbeads into an artificial dermis implanted into MIF KO mice accelerated procollagen production and capillary formation. These findings suggest that MIF is crucial in accelerating cutaneous wound healing and that MIF-impregnated gelatin microbeads represent a promising treatment to facilitate skin wound healing.

Expression of macrophage migration inhibitory factor in rat skin during embryonic development.

We have previously shown that human epidermal keratinocytes express macrophage migration inhibitory factor (MIF) mRNA, and immunohistochemical studies showed that MIF is expressed in human epidermis. To explore the possible pathophysiological roles of MIF in skin during rat fetal development, we examined the expression patterns of MIF during rat epidermal development using Northern blot analysis and in situ hybridization. Expression of MIF mRNA was first detected by in situ hybridization in the developing epidermis and hair germ cells from embryonic day (ED) 16. From ED 19, moderate levels of MIF expression were detected in the epidermis and epithelial sheath cells of growing hair follicles. In postnatal rat skin, higher MIF expression was detected in the epidermis and hair follicles on postnatal day 3. These observations were also confirmed by Northern blot analysis. Immunohistochemical analysis with an anti-MIF antibody showed a similar distribution to that of the mRNA. Our results suggest that MIF is associated with epidermal and hair follicle development.

Macrophage migration inhibitory factor is induced by thrombin and factor Xa in endothelial cells.

Macrophage migration inhibitory factor (MIF), a proinflammatory cytokine, has been shown to play a role in wound-healing processes. In this study, we investigated whether protease-activated receptor (PAR)-1 and PAR-2 mediated MIF expression in human endothelial cells. Thrombin, factor Xa (FXa), and trypsin induced MIF expression in human dermal microvascular endothelial cells and human umbilical vein endothelial cells, but other proteases, including kallikrein and urokinase, failed to do so. Thrombin-induced MIF mRNA expression was significantly reduced by the thrombin-specific inhibitor hirudin. Thrombin receptor activation peptide-6, a synthetic PAR-1 peptide, induced MIF mRNA expression, suggesting that PAR-1 mediates MIF expression in response to thrombin. The effects of FXa were blocked by antithrombin III, but not by hirudin, indicating that FXa might enhance MIF production directly rather than via thrombin stimulation. The synthetic PAR-2 peptide SLIGRL-NH(2) induced MIF mRNA expression, showing that PAR-2 mediated MIF expression in response to FXa. Concerning the signal transduction, a mitogen-activated protein kinase kinase inhibitor (PD98089) and a nuclear factor (NF)-kappaB inhibitor (SN50) suppressed the up-regulation of MIF mRNA in response to thrombin, FXa, and PAR-2 agonist stimulation, whereas a p38 inhibitor (SB203580) had little effect. These facts indicate that up-regulation of MIF by thrombin or FXa is regulated by p44/p42 mitogen-activated protein kinase-dependent pathways and NF-kappaB-dependent pathways. Moreover, we found that PAR-1 and PAR-2 mRNA expression in endothelial cells was enhanced by MIF. Furthermore, we examined the inflammatory response induced by PAR-1 and PAR-2 agonists injected into the mouse footpad. As shown by footpad thickness, an indicator of inflammation, MIF-deficient mice (C57BL/6) were much less sensitive to either PAR-1 or PAR-2 agonists than wild-type mice. Taken together, these results suggest that MIF contributes to the inflammatory phase of the wound healing process in concert with thrombin and FXa via PAR-1 and PAR-2.