Dynamics of depressive states among university students in Japan during the COVID-19 pandemic: an interrupted time series analysis.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic was reported to have increased depression among university students which was associated with impairments in their campus lives. This study examined changes in depressive states among Japanese university students during the COVID-19 pandemic. METHODS: A secondary data analysis from a factorial randomized controlled trial involving smartphone-based cognitive-behavioral therapy was performed. Six cohorts (N = 1626) underwent an 8-week intervention during the spring or autumn of 2019-2021, with a 9-month follow-up. We evaluated participants' depressive states weekly using the Patient Health Questionnaire-9 (PHQ-9) during the intervention, with monthly evaluations thereafter. The follow-up periods included Japan's four states of emergency (SOEs) to control COVID-19. Hypothesizing that SOEs caused a sudden worsening of depressive states, Study 1 compared the cohorts' PHQ-9 scores, and Study 2 employed time series analysis with a mixed-effects model to estimate identified changes in PHQ-9 scores. RESULTS: Although no changes in depressive states were observed in relation to the SOEs, Study 1 identified sudden increases in PHQ-9 scores at the 28-week evaluation point, which corresponded to the beginning of the new academic year for the three autumn cohorts. In contrast, the three spring cohorts did not exhibit similar changes. Study 2 showed that, for all three autumn cohorts (n = 522), the 0.60-point change was significant (95% CI 0.42-0.78; p < .001) at 28 weeks; that is, when their timeline was interrupted. CONCLUSIONS: While the results do not indicate any notable impact of the SOEs, they highlight the influence of the new academic year on university students' mental health during COVID-19. Trial registration UMIN, CTR-000031307. Registered on February 14, 2018.

Probe of the solar magnetic field using the "cosmic-ray shadow" of the sun.

We report on a clear solar-cycle variation of the Sun's shadow in the 10 TeV cosmic-ray flux observed by the Tibet air shower array during a full solar cycle from 1996 to 2009. In order to clarify the physical implications of the observed solar cycle variation, we develop numerical simulations of the Sun's shadow, using the potential field source surface model and the current sheet source surface (CSSS) model for the coronal magnetic field. We find that the intensity deficit in the simulated Sun's shadow is very sensitive to the coronal magnetic field structure, and the observed variation of the Sun's shadow is better reproduced by the CSSS model. This is the first successful attempt to evaluate the coronal magnetic field models by using the Sun's shadow observed in the TeV cosmic-ray flux.

Estradiol and raloxifene induce the proliferation of osteoblasts through G-protein-coupled receptor GPR30.

BACKGROUND: Although G-protein-coupled receptor, GPR30, has been considered as a G-protein-coupled estrogen receptor, conflicting results have been reported and the function of GPR30 in bone remains unresolved. The aim of this study was to clarify the functional role of GPR30 in osteoblasts using its derived cell line. METHODS AND RESULTS: Immunohistochemical study revealed that GPR30 is expressed in human osteoblasts. Human fetal osteoblast cell lines, hFOB cells, which express GPR30 but lack estrogen receptor, were used for the in vitro experiments. Estradiol or raloxifene induced the proliferation of hFOB cells, which was accompanied by the activation of mitogen-activated protein (MAP) kinase. Those proliferative effects were completely abrogated by the transfection of GPR30 small interfering RNA, while the transfection alone did not affect the cell viability. CONCLUSION: GPR30 is required for the proliferation of hFOB cells induced by estradiol or raloxifene. This proliferative effect was at least partly mediated via MAP kinase activation. These findings revealed a novel function of GPR30 in osteoblasts and might lead to a better understanding of how estrogen and selective estrogen receptor modulators show their osteoprotective effects.

Ischaemic colitis during interferon treatment for chronic hepatitis C: report of two cases and literature review.

Ischaemic colitis is known to be a severe emergency complication of interferon (IFN) therapy. However, as ischaemic colitis is an infrequent complication of IFN therapy, limited information is available regarding the safety of resuming IFN therapy after resolution of ischaemic colitis and subsequent recurrence. Here, we report two cases of ischaemic colitis during IFN therapy for chronic hepatitis C. Ischaemic colitis was fully healed within 1 week after its onset and IFN withdrawal, and IFN therapy was resumed following patients' wishes to do so. Ischaemic colitis did not recur after the resumption of IFN therapy, and sustained virological response was achieved in both patients. In this report, we also summarize the findings of 11 cases of IFN-associated ischaemic colitis (nine previously published cases plus our two cases) and review the clinical characteristics of ischaemic colitis during IFN therapy in patients with chronic hepatitis C.

Mechanistic correlations between two itch biomarkers, cytokine interleukin-31 and neuropeptide ß-endorphin, via STAT3/calcium axis in atopic dermatitis.

BACKGROUND: Itch is the cardinal symptom of atopic dermatitis (AD). ß-Endorphin, a neuropeptide, is increased in both AD skin and sera. Interleukin (IL)-31, an itch-relevant cytokine, activates IL-31 receptors in keratinocytes. However, how IL-31 and ß-endorphin interact in AD skin remains elusive. OBJECTIVES: To investigate the mechanistic interaction of IL-31 and ß-endorphin in AD. METHODS: This was a prospective cross-sectional study. We recruited adult patients with AD and controls according to Hanifin's AD criteria. Serum levels of IL-31 and ß-endorphin were measured by enzyme-linked immunosorbent assay. Expressions of IL-31 receptor A (IL-31RA) and ß-endorphin in the skin were assessed by immunohistochemistry. Their expression in the skin and blood was compared and correlated in patients with AD and in controls. We also treated primary keratinocytes with IL-31 and measured calcium influx, ß-endorphin production and signalling pathways to define their mechanistic interactions. RESULTS: ß-Endorphin was increased in the supernatant from IL-31-treated keratinocytes. IL-31 receptor activation resulted in calcium influx and STAT3 activation; pretreatment with STAT3 inhibitor stopped the increase of ß-endorphin. Notably, either replacement of extracellular calcium or treatment with 2-aminoethoxydiphenyl borate, an inhibitor for the store-operated channel, blocked STAT3 activation. We found higher levels of blood ß-endorphin and IL-31, which were significantly correlated, in patients with AD. Moreover, IL-31RA and ß-endorphin were increased and colocalized both in AD human skin and TPA-painted mouse skin. CONCLUSIONS: IL-31 receptor activation in keratinocytes induces calcium influx and STAT3-dependent production of ß-endorphin. These results might contribute to an understanding of the regulatory mechanisms underlying peripheral itch.

A phase II trial of capecitabine and docetaxel followed by 5-fluorouracil/epirubicin/cyclophosphamide (FEC) as preoperative treatment in women with stage II/III breast cancer.

BACKGROUND: Capecitabine (X) and docetaxel (T) have demonstrated a synergistic effect in preclinical models and a survival benefit in metastatic breast cancer. This study's purpose was to determine the efficacy of X and T followed by 5-fluorouracil/epirubicin/cyclophosphamide (FEC) in the preoperative setting. PATIENTS AND METHODS: Patients with stage II/III breast cancer received four cycles of XT (capecitabine 1650 mg/m(2) on days 1-14 and docetaxel 60 mg/m(2) on day 8 every 3 weeks), followed by four cycles of FEC (5-fluorouracil 500 mg/m(2), epirubicin 90 mg/m(2), and cyclophosphamide 500 mg/m(2) on day 1 every 3 weeks). Primary end points were the pathological complete response (pCR) rate and adverse drug reactions. RESULTS: Seventy-four patients were enrolled and 71 patients were assessable for clinical and pathological responses. The overall response rate was 91.5%. The pCR rate was 14.1% (10 of 71). Grade 3/4 neutropenia was observed in 32.4% of patients. The most common grade 3/4 non-hematologic adverse event was hand-foot syndrome, observed in 11.3% of patients. With 29 months median follow-up, 2-year disease-free survival was estimated 85% for all patients. CONCLUSION: These data indicate that the sequential combination of XT followed by FEC is a well-tolerated, effective neoadjuvant treatment of stage II/III breast cancer.

Non-sentinel lymph node status and prognosis of breast cancer patients with micrometastatic sentinel lymph nodes.

BACKGROUND: The prognostic significance of sentinel lymph node (SLN) micrometastases and the need for axillary lymph node dissection (ALND) on patients with micrometastases in SLNs remain controversial. METHODS: A prospective database of 657 breast cancer patients who underwent SLN biopsy (SLNB) was analyzed. SLNs were detected using a combined method of isosulfan blue dye and small-sized technetium-99m-labeled tin colloid. RESULTS: Micrometastases in SLNs were found in 50 (7.6%) of 657 patients. Twenty-nine (58.0%) of 50 patients with micrometastatic SLNs underwent ALND and no further metastases were found in non-sentinel lymph nodes. Among 21 patients (42.0%) with micrometastatic SLNs who decided to forego ALND, no axillary lymph node recurrence has been observed during a median follow-up time of 47 months. There is no significant difference in recurrence-free survival between the patients with micrometastatic and negative SLNs (p = 0.90). CONCLUSIONS: These data suggest that it may not be necessary to perform ALND on patients with micrometastases in SLNs and that the presence of micrometastases in SLNs may not be associated with prognosis.

Superiority of radioisotope over blue dye for sentinel lymph node detection in breast cancer.

BACKGROUND: Sentinel lymph node biopsy (SLNB) is commonly performed using radioisotopes and/or blue dye. However, it is still undefined which reagent is more suitable for identifying sentinel lymph nodes (SLN). PATIENTS AND METHODS: A consecutive series of 640 breast cancer patients who had undergone SLNB at the Keio University Hospital from 2001 to 2006 was analyzed. The SLN was identified by a combination of technetium-99m tin colloid and isosulfan blue dye. The correlation between clinicopathological factors and the distribution of radioisotopes and blue dye was analyzed. The single metastatic lymph node revealed by axillary lymph node dissection (ALND) is the 'true SLN', and the distribution of radioisotopes and blue dye to the 'true SLN' was also analyzed. RESULTS: Blue-dye- and radioisotope-positive SLN were identified in 79.6 and 94.7% of the patients, respectively. Taken together, SLN were identified in 625 patients (97.7%) by radioisotope and/or blue dye. No significant correlation was observed between clinicopathological features and the distribution of the reagents. ALND found 73 patients with single lymph node metastasis, and 73 'true SLN' were identified by blue dye in 65.7% (48/73), and by radioisotope in 95.9% (70/73) of the cases. CONCLUSION: These data suggest that radioisotopes are superior to blue dye in detecting SLN in breast cancer.

The entry of manganese ions into the brain is accelerated by the activation of N-methyl-D-aspartate receptors.

Manganese-enhanced magnetic resonance imaging (MEMRI) is receiving increased interest as a valuable tool for monitoring the physiological functions in the animal brain based on the ability of manganese ions to mimic calcium ions entering to excitable cells. Here the possibility that in vivo MEMRI can detect the entry of manganese ions (Mn2+) in the brain of rats behaving without intended stimulation is tested. This hypothesis was a result of the unexpected observation that Mn2+-dependent signal enhancement was dramatically suppressed in ketamine-anesthetized rats compared with other anesthetics, such as urethane, pentobarbital and isoflurane. The effects of noncompetitive N-methyl-d-aspartate receptor (NMDAR) antagonists, ketamine and MK-801, on MEMRI for MnCl2 injected rats were examined. Treatment with MK-801 suppressed the signal enhancement more effectively than with ketamine. NMDAR agonists, glutamate (100 mg/kg) and N-methyl-d-aspartate (NMDA) (35 mg/kg), enhanced the signal intensities on MEMRI, and this signal enhancement was completely antagonized by MK-801. The systemic administration of the competitive NMDAR antagonist, D-2-amino-5-phosphono-pentanoate (D-AP5), which does not cross the blood-brain barrier (BBB), showed no effects on the signal enhancement induced by NMDA and glutamate. A selective AMPA receptor (AMPAR) antagonist, 1,2,3,4-tetrahydro-6-nitro-2,3-dioxo-benzo[f]quinoxaline-7-sulfonamide (NBQX), did not block the signal enhancement. These data indicated that the Mn2+-dependent signal enhancement took place as a result of the activation of glutamatergic neurons through NMDAR, but not through AMPAR in the brain.

A randomized study of screening for ovarian cancer: a multicenter study in Japan.

Ovarian cancer is common in women from developed countries. We designed a prospective randomized controlled trial of ovarian cancer screening to establish an improved strategy for the early detection of cancers. Asymptomatic postmenopausal women were randomly assigned between 1985 and 1999 to either an intervention group (n = 41,688) or a control group (n = 40,799) in a ratio of 1:1, with follow-up of mean 9.2 years, in Shizuoka district, Japan. The original intention was to offer women in the intervention group annual screens by gynecological examination (sequential pelvic ultrasound [US] and serum CA125 test). Women with abnormal US findings and/or raised CA125 values were referred for surgical investigation by a gynecological oncologist. In December 2002, the code was broken and the Shizuoka Cohort Study of Ovarian Cancer Screening and Shizuoka Cancer Registry were searched to determine both malignant and nonmalignant diagnoses. Twenty-seven cancers were detected in the 41,688-screened women. Eight more cancers were diagnosed outside the screening program. Detection rates of ovarian cancer were 0.31 per 1000 at the prevalent screen and 0.38-0.74 per 1000 at subsequent screens; they increased with successive screening rounds. Among the 40,779 control women, 32 women developed ovarian cancer. The proportion of stage I ovarian cancer was higher in the screened group (63%) than in the control group (38%), which did not reach statistical significance (P = 0.2285). This is to our knowledge the first prospective randomized report of the ovarian cancer screening. The rise in the detection of early-stage ovarian cancer in asymptomatic postmenopausal women is not significant, but future decisions on screening policy should be informed by further follow-up from this trial.

Ex vivo coagulation test on tissue factor-expressing cells with a calibrated automated thrombogram.

A calibrated automated thrombogram is not affected by the turbidity of platelet and cell preparations because the measurement is based on fluorescence. To examine conditions that mimic the physiological state, we investigated thrombograms that show thrombin generation on tissue factor (TF)-bearing cells. An increase in the number of J82 cells did not affect the endogenous thrombin potential (ETP) of normal plasma, although the lag time (LT), the peak height, and the time to peak (ttPeak) did depend on cell concentration. When 5 parameters of coagulation factor-deficient plasmas were plotted on a radar graph, the thrombogram pattern of factor XI (FXI)-deficient plasma became slightly reduced. The thrombogram did not improve when washed normal platelets or washed normal platelets with adenosine diphosphate (ADP) were added. FVII-depleted plasma, FVIII-deficient plasma, and FIX-deficient plasma showed remarkably reduced peak heights, ttPeaks, and times to the end of thrombin generation (start tails). The thrombogram of FVII-depleted plasma was characterized by a remarkably prolonged LT, unlike the patterns of FVIII- or FIX-deficient plasma and FXI-depleted plasma. The ETP of FVIII- and FIX-deficient plasma, but not FVII-depleted plasma, improved significantly upon addition of washed normal platelets or washed normal platelets with ADP. The thrombograms of coagulation factor-deficient plasma containing TF-bearing cells differed from those for recombinant TF and phospholipid in the liquid phase. We suggest that thrombograms using TF-bearing cells can be a useful ex vivo test, because this experimental model may be analogous to most coagulation processes in vivo.

Is atriopeptin a physiological or pathophysiological substance? Studies in the autoimmune rat.

Atriopeptin (AP), a natriuretic-diuretic and vasodilatory peptide, is synthesized and secreted from mammalian atria. The definitive role of this peptide on cardiovascular physiology and pathophysiology has yet to be determined. We developed a population of autoimmune rats sensitized against their own AP to evaluate the consequences of prolonged AP deficiency on physiological and pathophysiological processes. Natriuresis in response to acute intravenous volume expansion was inhibited in the autoimmune rat, however, natriuresis produced by chronic oral salt loading was not suppressed in these animals. Plasma AP increased threefold in the spontaneously hypertensive rat when evaluated as a function of blood pressure. Immunization of these rats had no effect on the rate of development, magnitude of their developing hypertension, or their daily sodium excretion when compared with nonimmunized controls. Mineralocorticoid escape occurred during desoxycorticosterone acetate administration to rats. The ability of rats to escape from the sodium-retaining effects of this steroid was not affected by prior immunization against AP. These results suggest that AP is an important natriuretic substance in response to acute intravascular volume loading. However, atriopeptin does not appear to be involved in the natriuretic response to chronic intravascular volume loading, blood pressure regulation, or mineralocorticoid escape.

Chronic treatment with interleukin-1 beta induces coronary intimal lesions and vasospastic responses in pigs in vivo. The role of platelet-derived growth factor.

Studies in vitro have suggested that inflammatory cytokines may play an important role in the pathogenesis of atherosclerosis. However, little is known about their effects in vivo. Thus, the present study was designed to determine in vivo what histological and functional changes may be induced by chronic treatment with IL-1 beta, one of the major inflammatory cytokines, and also to clarify what mechanisms are involved in those changes. Under aseptic conditions, proximal segments of the left porcine coronary arteries were gently wrapped with cotton mesh absorbing Sepharose beads either with or without recombinant human IL-1 beta. From 1 to 4 wk after the operation, coronary vasospastic responses to intracoronary serotonin or histamine were noted at the IL-1 beta-treated site but not at the control site. Histologically, intimal thickening was greater at the IL-1 beta-treated site than at the control site. Those functional and histological changes induced by the chronic treatment with IL-1 beta were significantly inhibited by the simultaneous treatment with a neutralizing antibody to either IL-1 beta or PDGF. These results indicate that chronic treatment with Il-1 beta induces coronary intimal lesions and vasospastic responses in porcine coronary arteries in vivo and also suggest that these changes are substantially mediated by PDGF.

Involvement of Sp-1 in the regulation of the Id-1 gene during trophoblast cell differentiation.

Id-1, a member of the helix-loop-helix transcription factor family, inhibits the differentiation of Rcho-1 cells, which were derived from rat choriocarcinoma and consist of trophoblast stem cells. Id-1 is expressed at a high level in undifferentiated trophoblast stem cells and then down-regulated during early differentiation, and is thought to be a key regulator in the trophoblast giant-cell differentiation pathway. In this study, we analyzed the signaling mechanism regulating the high expression levels of Id-1 in undifferentiated Rcho-1 cells. Promoter deletion analysis revealed that a 31-bp sequence (Box-2 region), located between -200 and -169bp in the Id-1 promoter is necessary for the promoter activity. Electrophoretic mobility shift assays and DNA affinity precipitation assays showed that Box-2-binding activity was decreased during differentiation and that Sp-1 protein bound to this sequence. The protein level of Sp-1 was decreased during the differentiation. These results suggest that the Sp-1 protein level may regulate the Box-2-binding activity and the trophoblast giant-cell differentiation.

Serum CA125 level before the development of ovarian cancer.

BACKGROUND: Little is known about the natural history of ovarian cancer with respect to the change of serum CA125 level. METHODS: The Shizuoka Cohort Study on Ovarian Cancer Screening (SCSOCS) Trial contains approximately 100,000 data on serum tumor marker CA125 prospectively obtained from more than 70,000 women. We reviewed the clinical charts and collected serum samples 2 months to 9.4 years prior to the surgery were available. RESULTS: In 396 (95%) of the 419 patients with ovarian cancer, one serum sample was present before the diagnosis (mean, 4.1 years). The change of CA125 level before the diagnosis of ovarian cancer could be clearly separated into two groups according to the length of the following intervals: 47% (107/228) of patients with non-serous-type ovarian cancers develop secondarily from slightly elevated CA125 level (35

STAT3-mediated constitutive expression of SOCS3 in an undifferentiated rat trophoblast-like cell line.

In the trophoblast, constitutive expression of SOCS3 is important for the negative regulation of trophoblast giant cell differentiation. In this study, we analyzed the signaling pathway regulating the constitutive SOCS3 expression in undifferentiated Rcho-1 cells, which were derived from rat choriocarcinoma and consist of trophoblast stem cells that are capable of differentiating to trophoblast giant cells in vitro. PD98059, an MEK inhibitor, repressed the SOCS3 expression but AG490, a JAK2 inhibitor, did not. Promoter deletion analysis revealed that the STAT response element (SRE) in the SOCS3 promoter is necessary for the promoter activity. Overexpression of STAT3 increased the SOCS3 promoter activity, whereas expression of dominant-negative STAT3 reduced it. Constitutive STAT3 tyrosine phosphorylation that was not inhibited by either AG490 or PD98059 was demonstrated. Electrophoretic mobility shift assays showed the existence of a protein that bound to SRE and was supershifted with STAT3 antibody. This binding reaction was inhibited by neither AG490 nor PD98059. These findings imply that the ERK/MAPK pathway and STAT3 are involved in the constitutive activation of SOCS3 in undifferentiated Rcho-1 cells. Moreover, they indicate that the constitutive STAT3 tyrosine phosphorylation and the DNA binding activity of STAT3 do not depend on the ERK/MAPK or JAK kinase pathway. These results suggest that a trophoblast-specific STAT3 activation pathway is important for the regulation of giant cell differentiation.

Distribution and toxicity of mercury in rats after oral administration of mercury-contaminated whale red meat marketed for human consumption.

Toothed-whales and dolphins have been hunted for human consumption in Japan, and their muscles (red meats) are highly contaminated with mercury (Hg). We investigated the distribution and toxicity of Hg in rats after oral administration of Hg-contaminated whale red meat marketed for human consumption in Japan. Rats were orally administered the red meat homogenate for seven consecutive days (0.5 g red meat/kg-bw/day). The red meat administered to rats contained 81microg/g of total mercury (T-Hg) and 13.4 microg/g of methyl mercury (M-Hg). This dose corresponds to the human consumption of 210 g red meat/60 kg-bw/week, exceeding by about 29 times the provisional tolerable weekly intake of M-Hg at 1.6 microg/kg-bw/week set by JECFA [JECFA, 2003. Joint FAO/WHO expert committee on food additives. 61st meeting, Rome]. Twenty-four hours after the last administration, the distribution of T-Hg in rat organs and biochemical parameters in serum were analyzed. The administration of red meat significantly elevated T-Hg concentrations in the liver, kidney, erythrocytes, cerebral cortex and medulla oblongata from the control levels but did not elevate the T-Hg concentration in serum, showing the typical distribution pattern of M-Hg, not of inorganic Hg. The administration slightly but significantly increased GTP activity and P concentration and decreased BUN concentration in serum, although no abnormalities were observed in rat body weight gain and movement during the 7 days. The occasional consumption of red meat from small cetaceans, therefore, could pose a health problem for not only pregnant women but also for the general population.

Endothelin-1 is not involved in serotonin-induced coronary spasm in a swine model.

OBJECTIVES: The role of endothelin-1 (ET-1) in the pathogenesis of coronary artery spasm is not well understood. We aimed to determine if ET-1 is involved in serotonin-induced coronary spasm in the swine model. METHODS: In 10 miniature pigs, a segment of the left anterior descending coronary artery was denuded and irradiated with X-ray. Three months after endothelial denudation, coronary vasomotion was assessed in vivo by quantitative arteriography. RESULTS: Intracoronary serotonin at 10 micrograms/kg provoked coronary spasm (augmented narrowing of the luminal diameter) at the denuded site (diameter reduction 93 +/- 4%) but not at the non-denuded control site (19 +/- 4%, P < 0.01) associated with ST segment elevation in the region perfused by the denuded artery. Intracoronary administration of ET-1 at 25 ng/kg caused mild vasoconstriction of the denuded (26 +/- 4) and non-denuded site (16 +/- 3%, n.s.), but provoked ST segment elevation in the regions perfused by both the denuded and non-denuded arteries. The treatment with an endothelin antagonist (BQ123 0.1 mg/kg) significantly attenuated coronary vasoconstriction and ST segment elevation evoked with ET-1, but did not alter serotonin-induced vasoconstriction either at the denuded or control site. CONCLUSIONS: The results of this study suggest that endogenous ET-1 may not be involved in the pathogenesis of serotonin-induced coronary spasm in our swine model.

Expression of osteoprotegerin (osteoclastogenesis inhibitory factor) in cultures of human dental mesenchymal cells and epithelial cells.

Osteoprotegerin (OPG)/osteoclastogenesis inhibitory factor (OCIF) inhibits osteoclast differentiation, activity, and survival; therefore OPG/OCIF may regulate the resorption of dental hard tissues, such as alveolar bone, cementum, and dentin. To investigate this issue, reverse transcriptase-polymerase chain reaction using specific primers for OPG/OCIF was performed with total RNAs isolated from human gingival keratinocytes (HGKs), human gingival fibroblasts (HGFs), human periodontal ligament cells (HPDLs), and human pulp cells (HPCs) in culture. PCR products were found in HGFs, HPDLs, and HPCs, but not in HGKs, and the DNA sequence of these products was 100% identical to the reported sequence of the OPG gene. Northern blot analyses also showed that HGFs, HPDLs, and HPCs, but not HGKs, expressed OPG/OCIF transcripts of approximately 2.5 kb. Interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) increased OPG/OCIF mRNA levels in a dose-and time-dependent manner in HPDL. After 12 h of treatment, IL-1beta at 3 ng/ml and TNF-alpha at 3 ng/ml increased OPG/OCIF mRNA expression by 190% and 110%, respectively, with a maximal effect. The stimulatory effects of IL-1beta and TNF-alpha were also seen in HPC. However, IL-6 and transforming growth factor-beta had little effect on OPG/OCIF mRNA levels in HPDL. These findings suggest that OPG/OCIF synthesized by dental mesenchymal cells locally regulates the resorption of dental hard tissues through cytokines.