Lack of association between risk of biliary tract cancer and circulating IGF (Insulin-like Growth Factor) -I, IGF-II or IGFBP-3 (IGF-binding Protein-3): A nested case-control study in a large scale cohort study in Japan.

Biliary tract cancer, encompassing gallbladder and bile duct cancers, has a poor prognosis, but little is known of the etiology. A nested case-control study was here conducted to evaluate the association between serum levels of IGF-I, IGF-II and IGFBP-3 and death from biliary tract cancer. In a large scale cohort study, 35 gallbladder and 42 bile duct cancers were observed during the follow-up. For each subject in the case group, 1-3 control subjects (228 in total) were selected randomly, matched for sex, age (as near as possible) and residential area. The subjects were divided into tertiles by circulating levels of IGF-I, IGF-II or IGFBP-3. Using conditional logistic regression, risks among the tertiles were compared adjusted for defecation, smoking and drinking habits. No remarkable differences in risks of gallbladder or bile duct cancer were observed among tertiles of IGF-I or IGF-II, and no remarkable trend was observed. Circulating IGFBP-3 showed an inverse U-shape association with gallbladder cancer and a U-shaped one with bile duct cancer. Associations between IGF-I or IGF-II and gallbladder or bile duct cancer thus were lacking or very weak. The observed U- and inverse U-shaped association of IGFBP-3 with the cancers is not suggestive of any meaningful relationships.

Serum soluble fas levels and superoxide dismutase activity and the risk of death from pancreatic cancer: A nested case-control study within the Japanese Collaborative Cohort Study.

In a search for novel circulating biomarkers for pancreatic cancer, we examined the association between serum soluble Fas (sFas) levels and superoxide dismutase (SOD) activity and the risk of death from pancreatic cancer in a nested case-control study within the Japanese Collaborative Cohort Study. Case subjects were 68 persons who were free of morbidity, had provided a blood sample at baseline (1988-1990), and subsequently died from pancreatic cancer before December 31, 1997. Control subjects were 199 matched persons who were selected from the remaining participants in the cohort. Conditional logistic regression models were used to estimate age-adjusted and multivariate-adjusted odds ratios (ORs) and their 95% confidence intervals (CIs). No statistically significant differences were noted in mean sFas levels (p=0.11) and SOD activity (p=0.42) between cases and controls. Overall, neither serum sFas levels nor SOD activity were associated with the risk of pancreatic cancer deaths, after adjustment for area, BMI, cigarette smoking, and history of diabetes. Furthermore, no significant risk trends were noted. Our results do not support the hypothesis that serum sFas levels and SOD activity are associated with pancreatic cancer risk.

Green tea consumption and the risk of pancreatic cancer in Japanese adults.

OBJECTIVE: Green tea polyphenols have been shown to inhibit tumor growth in animal and in vitro studies. We examined the relationship between green tea consumption and the risk of death from pancreatic cancer in a large Japanese cohort. METHODS: At baseline (1988-1990), study participants reported the frequency and amount of green tea consumption during the past year. They were followed-up for mortality until December 31, 2003. Relative risk and 95% confidence intervals were calculated from Cox proportional hazard models. RESULTS: During an average follow-up of 13 years, we observed 292 pancreatic cancer deaths. In men and women combined, the relative risk was 1.23 (95% confidence interval, 0.84-1.80) for participants who consumed 7 or more cups of green tea per day as compared with those who consumed less than 1 cup per day, after adjustment for potential confounding factors. No significant trend in risk reduction was noted, with increasing consumption of green tea. We found no inverse association between cups of green tea consumed per day and the risk of pancreatic cancer in either men or women. CONCLUSIONS: Our findings do not support the hypothesis that green tea consumption is associated with decreased risk of pancreatic cancer in humans.

Cigarette smoking, alcohol drinking and the risk of gallbladder cancer death: a prospective cohort study in Japan.

Gallbladder cancer is a rare cancer with a poor prognosis, and few risk factors have been identified to date. This prospective study was conducted to evaluate the association of cigarette smoking and alcohol consumption with the risk of gallbladder cancer death. A baseline survey in 45 areas throughout Japan was conducted from 1988 to 1990 using a self-administered questionnaire, and a total of 113,496 participants (65,740 women) aged 40-89 years at entry were followed for 15 years. During the follow-up period, 165 gallbladder cancer deaths (95 women) were observed. Among women, the hazard ratio (HR) [95 percent confidence interval: 95% CI] of current smoker was 2.00 [0.91-4.42], when adjusted for age and drinking. There was no clear association between alcohol consumption and the risk. Among men, HR of current smoker was 2.27 [1.05-4.90]. HRs of those who smoked 21 cigarettes or more per day and those with 801-1,000 cigarette-years were 3.18 [1.18-8.53] and 3.44 [1.40-8.45], respectively, and positive linear associations were observed between that risk and the number of cigarettes per day (p for trend = 0.007) or "cigarette-years" (p for trend = 0.012). The alcohol dose was linearly associated with risk (p for trend = 0.004), where the HR among those who consumed 72.0 g or more of alcohol per day was 3.60 [1.29-9.85]. Among both men and women, cigarette smoking may elevate the risk of death from gallbladder cancer. Drinking may pose an elevated risk among men, but that seems to be less true among women.

Obesity, physical activity and the risk of pancreatic cancer in a large Japanese cohort.

It is unclear whether body mass index (BMI) and physical activity are associated with the risk of pancreatic cancer in Asian populations. We examined these associations in the Japanese Collaborative Cohort Study for Evaluation of Cancer Risk. Our cohort study included 110,792 Japanese men and women at enrollment (1988-1990). Data on height, body weight (at baseline and at age 20 years) and physical activity were obtained from a questionnaire. Cox proportional hazards models were used to estimate the relative risks of pancreatic cancer mortality. We observed a total of 402 pancreatic cancer deaths during the follow-up period. Men with a BMI of 30 or more at age 20 years had a 3.5-fold greater risk compared with men with a normal BMI. Women with a BMI of 27.5-29.9 at baseline had approximately 60% increased risk compared with women with a BMI of 20.0-22.4. In men, weight loss of 5 kg or more between 20 years of age and baseline age was associated with an increased risk of pancreatic cancer death. In contrast, women with weight loss of 5 kg or more over the same period had a decreased risk. Physical activity was not associated with pancreatic cancer risk in either men or women. Obesity in young adulthood may be associated with an increased risk of death from pancreatic cancer in Japanese men. The risk of pancreatic cancer in relation to BMI seems to differ according to sex and the period over which BMI was measured.

Dietary habits and pancreatic cancer risk in a cohort of middle-aged and elderly Japanese.

Few epidemiological studies have examined associations between diet and pancreatic cancer in Japan. In the Japan Collaborative Cohort Study for Evaluation of Cancer Risk, we evaluated the relationship between dietary factors, including meat, vegetable, and fruit intake, and the risk of pancreatic cancer deaths. Among the original cohort established between 1988 and 1990, 46,465 men and 64,327 women aged 40-79 yr were followed-up through December 31,1999. During 1,042,608 person-years of follow-up, we documented 300 deaths from pancreatic cancer. A 33-item food-frequency questionnaire was used to assess dietary intake at the baseline survey. Cox proportional-hazards models were used to estimate the relative risks of pancreatic cancer death in relation to the intake frequency of food items. We did not observe an overall association between meat intake and pancreatic cancer risk. Except for a 50% decrease in risk associated with high fruit intake among men, we did not find other significant inverse relationships between vegetable and fruit intake and pancreatic cancer risk. Smoking did not modify the associations with dietary habits. Our study suggested that high consumption of pickles and wild edible plants, mainly bracken, might be related to increased pancreatic cancer risk; however, this finding should be confirmed in other epidemiological studies.

Factors associated with intentions to adhere to colorectal cancer screening follow-up exams.

BACKGROUND: To increase adherence rate to recommendations for follow-up after abnormal colorectal cancer (CRC) screening results, factors that inhibit and facilitate follow-up must be identified. The purpose of this study was to identify the factors associated with intention to adhere to CRC screening follow-up exams. METHODS: During a 4-week period in October 2003, this survey was conducted with 426 subjects participating in a community-based CRC screening program in Nagano, Japan. Study measures included intention to adhere to recommendation for clinical follow-up in the event of an abnormal fecal occult blood test (FOBT) result, perceived susceptibility and severity of CRC, perceived benefits and barriers related to undergoing follow-up examination, social support, knowledge of CRC risk factors, health status, previous CRC screening, personality and social demographic characteristics. Univariate and multivariate logistic regression analyses on intention to adhere to recommendations for follow-up were performed. RESULTS: Among the 288 individuals analyzed, approximately 74.7% indicated that they would definitely adhere to recommendations for follow-up. After controlling for age, gender, marital status, education, economic status, trait anxiety, bowel symptoms, family history of CRC, and previous screening FOBT, analyses revealed that lower levels of perceived barriers, higher levers of perceived benefits and knowledge of CRC risk factors were significantly associated with high intention respectively. CONCLUSION: The results of this study suggest that future interventions should focus on reducing modifiable barriers by clarifying misperceptions about follow-up, promoting the acceptance of complete diagnostic evaluations, addressing psychological distress, and making follow-up testing more convenient and accessible. Moreover, educating the public regarding the risk factors of CRC and increasing understanding of the benefits of follow-up is also important.

Association of menstrual and reproductive factors with pancreatic cancer risk in women: findings of the Japan Collaborative Cohort Study for Evaluation of Cancer Risk.

BACKGROUND: The etiology of pancreatic cancer remains largely unknown. We examined the association of pancreatic cancer deaths with menstrual and reproductive factors in a cohort study involving Japanese women. METHODS: A total of 63,273 women were followed up for mortality from 1988 to 1999. Information on menstrual and reproductive factors was obtained by a questionnaire survey at baseline. Cox proportional-hazards models were used to estimate the relative risks (RRs) and 95% confidence intervals (CIs) for death from pancreatic cancer in relation to menstrual and reproductive factors. RESULTS: During 631,401 person-years of follow-up, 154 women died from pancreatic cancer. Parity was not significantly associated with the risk of death from pancreatic cancer; the RR was 0.80 (95% CI, 0.31-2.11) for women with six or more births compared with women with zero or one birth. We found no significant overall association with other reproductive factors, including pregnancy, age at first birth, and menopause. The risk appeared to increase with increasing age at menarche; the RR was 1.49 (95% CI, 0.95-2.34) for women who had menarche after 16 years of age compared to those who had menarche before they were 15 years old. CONCLUSIONS: Our prospective data indicate that menstrual and reproductive factors are not associated with the risk of death from pancreatic cancer among Japanese women.

Serum transforming growth factor-beta1 levels and pancreatic cancer risk: a nested case-control study (Japan).

OBJECTIVE: To examine the relationship of baseline levels of serum TGF-beta1 to the subsequent risk of death from pancreatic cancer in a nested case-control study. METHODS: The cases were 85 persons who had provided a blood sample at baseline and subsequently died of pancreatic cancer during the study period. For each case, three controls were randomly selected from among the cohort participants, and were matched for each case by sex, age (+/-1 year), and study area. Serum TGF-beta1 levels were measured with enzyme-linked immunosorbent assay (ELISA). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated from conditional logistic models. RESULTS: The mean of serum TGF-beta1 levels was significantly higher among cases than among controls (p = 0.01). Individuals with serum TGF-beta1 levels in the highest quartile had a 2.5-fold increase in risk as compared with those in the lowest quartile (OR, 2.5; 95% CI, 0.9-6.9), after adjustment for month of blood draw, cigarette smoking, body mass index and history of diabetes. Excluding 12 pancreatic cancer deaths that occurred within three years of follow-up did not alter the positive association. CONCLUSION: Our prospective data indicate that high serum TGF-beta1 levels may be associated with an increased risk of death from pancreatic cancer.

Evaluation of data in terms of two-dimensional random walk model: interaction between NADH-cytochrome b5 reductase and cytochrome b5.

Normally, bimolecular reactions are analyzed in terms of the Smoluchowski theory. However, when one attempts to generalize this analysis to cases where diffusion proceeds in two other than in three dimensions, one soon encounters severe conceptual difficulties. Although kinetic studies of membrane enzymes are generally difficult because the usual kinetic formalism refers to nonaggregated homogenous solutions, a major goal of our research is to define the molecular mechanism(s) by which alterations in membrane-bound substrate contents affect the enzyme activity in the same membrane. For that purpose, a simplified random-walk model was adopted in the present work. The enzyme reaction in the two-dimensional membrane could be calculated theoretically by applying the classical analysis of heat equation. As a result, the theoretical rate equation well accounting experimental findings was derived on the model of the liver microsomal NADH-cytochrome b5 reductase reaction. Furthermore, it was found that the modification of the simple rigid-sphere collision theory by including a term called the steric factor was not necessary in this derived equation.

Alcohol consumption and mortality among middle-aged and elderly Japanese men and women.

PURPOSE: We conducted a prospective cohort study to examine the association between alcohol intake and the risk of all-cause mortality among middle-aged and elderly Japanese men and women. METHODS: At baseline (1988-1990), a total of 110,792 Japanese men and women aged 40 to 79 years were asked to complete a questionnaire that included information on alcohol intake, and were followed up for all-cause mortality through December 31, 1999. Relative risks (95% confidence interval) were calculated using Cox proportional-hazards models. RESULTS: The risk of all-cause mortality was lowest among current drinkers with an alcohol intake of 0.1 to 22.9 g/d (RR, 0.80; 95% CI, 0.72-0.88 for men; and RR, 0.88; 95% CI, 0.77-1.00 for women). Excessive mortality associated with heavy drinking (> or = 69 g/d) was observed for cancer, cardiovascular disease and injuries and other external causes in men, while significantly reduced mortality with light drinking was seen for cancer in men and CVD in women. For men, the benefit associated with light alcohol consumption (< 23 g/d) was more apparent among nonsmokers than among smokers. CONCLUSION: Our prospective data show a 12% to 20% decreased risk of all-cause mortality in both Japanese men and women who consumed less than 23 g/d of alcohol (approximately 2 drinks), although heavy drinking increased that risk.

Serum pepsinogen values and Helicobacter pylori status among control subjects of a nested case-control study in the JACC study.

BACKGROUND: Helicobacter pylori infection and serum pepsinogen values are strongly related with stomach cancer. The aim of this study was to know what were these factors among general population. METHODS: Subjects were randomly selected 633 control subjects in a nested case-control study for risk of stomach cancer. Most of them were from rural areas of Japan. Using frozen sera, pepsinogen I (PG I) and II (PG II) values and H. pylori antibody were measured. Those with PG I less than 50 ng/mL and the ratio of PG I to PG II (PG I/II) was less than 2.0 were defined as severe, those with PG I less than 70 ng/ml and PG I/II less than 3.0 were defined as mild and the other subjects were defined as no serological atrophy. RESULTS: About 70% of the subjects were H. pylori seropositive and the seroprevalence did not depend on age or sex. Percentages of those with severe serological atrophy increased with age from 10% in those aged 40-49 years to 38% in 70 and more, and percentages of those with mild serological atrophy were about 30% independent of age. CONCLUSIONS: The subjects, who were expected to represent populations of rural area of Japan, had high prevalence of both H. pylori infection and serological atrophy of gastric mucosa. These facts should be considered in discussing results of the nested case-control study.

Ab initio model study on acetylcholinesterase catalysis: potential energy surfaces of the proton transfer reactions.

Ab initio molecular orbital (MO) and hybrid density functional theory (DFT) calculations have been applied to the initial step of the acylation reaction catalyzed by acetylcholinesterase (AChE), which is the nucleophiric addition of Ser200 in catalytic triads to a neurotransmitter acetylcholine (ACh). We focus our attention mainly on the effects of oxyanion hole and Glu327 on the potential energy surfaces (PESs) for the proton transfer reactions in the catalytic triad Ser200-His440-Glu327. The activation barrier for the addition reaction of Ser200 to ACh was calculated to be 23.4 kcal/mol at the B3LYP/6-31G(d)//HF/3-21G(d) level of theory. The barrier height under the existence of oxyanion hole, namely, Ser200-His440-Glu327-ACh-(oxyanion hole) system, decreased significantly to 14.2 kcal/mol, which is in reasonable agreement with recent experimental value (12.0 kcal/mol). Removal of Glu327 from the catalytic triad caused destabilization of both energy of transition state for the reaction and tetrahedral intermediate (product). PESs calculated for the proton transfer reactions showed that the first proton transfer process is the most important in the stabilization of tetrahedral intermediate complex. The mechanism of addition reaction of ACh was discussed on the basis of theoretical results.

Bowel movement frequency, medical history and the risk of gallbladder cancer death: a cohort study in Japan.

Few risk factors for gallbladder cancer have been identified with sufficient statistical power, because this cancer is rare. The present study was conducted to evaluate the association of bowel movement frequency and medical history with the risk of death from gallbladder cancer using the data set from a large-scale cohort study. A total of 113,394 participants (42.0% males), aged 40 to 89 years, were followed up for 11 years. Information on the medical history of selected diseases, history of blood transfusions, frequency of stools, and tendency toward diarrhea at baseline was collected through a self-administered questionnaire. The Cox proportional hazard model was used to estimate the hazard ratio (HR). During the follow-up period, a total of 116 deaths (46 males, 70 females) from gallbladder cancer were identified. After adjustments for age and gender, history of hepatic disease (HR: 2.28; 95% confidence intervals (95% CI): 1.24-4.21), frequency of stool, and tendency toward diarrhea (HR: 0.26; 95% CI: 0.08-0.83) were found to be significantly associated with the risk of death from gallbladder cancer. Compared with those who had a stool at least once a day, the HR was 2.06 (95% CI: 0.82-5.18) for those who had a stool less than once in 6 days (P for trend = 0.050). In this prospective study, constipation and a history of hepatic disease were found to elevate the risk of gallbladder cancer death, whereas a tendency toward diarrhea diminished it.

Serum insulin-like growth factor-I, insulin-like growth factor binding protein-3, and the risk of pancreatic cancer death.

Recent epidemiological studies have shown that high serum levels of insulin-like growth factor-I (IGF-I) are associated with an increased risk of lung, colon, breast and prostate cancer. Since very few studies have addressed the role of serum levels of IGF-I in the development of pancreatic cancer, we conducted a nested case-control study to examine this association. The analysis involved 69 case subjects who died from pancreatic cancer during the follow-up period of the study, and 207 control subjects matched for sex, age(+/-1 year) and study area, selected randomly from a cohort of 10364 individuals. Serum levels of IGF-I and IGF binding protein-3 (IGFBP-3) were measured by immunoradiometric assay, using commercially available kits. The odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using conditional logistic models. The levels of IGF-I were positively correlated with IGFBP-3 (r=0.55). There was a positive, but statistically insignificant association between serum levels of IGF-I and risk of death from pancreatic cancer, with subjects in the highest quartile having an OR of 2.31 (95% CI=0.70-2.64) compared to those in the lowest quartile. The risk of pancreatic cancer death increased significantly with increasing serum levels of IGFBP-3 (trend p=0.03). Further adjustment for IGFBP-3 or IGF-I slightly attenuated the positive associations. This nested case-control study showed that high serum levels of IGF-I and IGFBP-3 may be associated with an increased risk of death from pancreatic cancer.

Macrophage migration inhibitory factor up-regulates the expression of interleukin-8 messenger RNA in synovial fibroblasts of rheumatoid arthritis patients: common transcriptional regulatory mechanism between interleukin-8 and interleukin-1beta.

OBJECTIVE: Interleukin-8 (IL-8) plays an important role in the migration of inflammatory cells into the synovium and joint fluids in rheumatoid arthritis (RA). This study was undertaken to investigate the IL-8 inductive activity of the macrophage migration inhibitory factor (MIF) in RA synovial fibroblasts. The regulatory mechanism of IL-8 was compared with that of IL-1beta. METHODS: MIF-induced IL-8 and IL-1beta transcriptional activation was studied in RA synovial fibroblasts by Northern blot analysis, enzyme-linked immunosorbent assay, and electromobility shift assay. The effect of anti-MIF antibody administration on murine passive collagen-induced arthritis (CIA) was also evaluated by histologic examination and reverse transcriptase-polymerase chain reaction. RESULTS: MIF up-regulated the IL-8 messenger RNA (mRNA) and protein levels in a dose-dependent manner. The IL-8 mRNA up-regulation started 1 hour poststimulation by MIF, and reached a maximum level at 6 hours. IL-1beta mRNA was also up-regulated by MIF. The mRNA up-regulation of IL-8 and IL-1beta by MIF was inhibited by 2 tyrosine kinase inhibitors, a protein kinase C (PKC) inhibitor, an activator protein 1 (AP-1) inhibitor, and by an NF-kappaB inhibitor. A cAMP-dependent kinase inhibitor did not inhibit it. MIF enhanced AP-1 and NF-kappaB binding activities in a dose-dependent manner. Passive CIA enhanced mRNA levels of macrophage inflammatory protein 2 and cytokine-induced neutrophil chemoattractants and, moreover, migration and proliferation of inflammatory cells within the synovium, which were suppressed by administration of an anti-MIF antibody. CONCLUSION: MIF may play an important role in the migration of inflammatory cells into the synovium of rheumatoid joints via induction of IL-8. MIF up-regulates IL-8 and IL-1beta mRNA via tyrosine kinase-, PKC-, AP-1-, and NF-kappaB-dependent pathways.

Inhibition of joint inflammation and destruction induced by anti-type II collagen antibody/lipopolysaccharide (LPS)-induced arthritis in mice due to deletion of macrophage migration inhibitory factor (MIF).

OBJECTIVE: Previous studies have demonstrated that neutralization of macrophage migration inhibitory factor (MIF) by anti-MIF antibody decreases joint destruction in the collagen-induced arthritis model. The present study was undertaken to investigate whether selective deletion of MIF inhibits inflammation and joint destruction of the anti-type II collagen antibody (anti-CII Ab)/lipopolysaccharide (LPS)-induced arthritis in mice, in order to determine the role of this cytokine in inflammatory arthritis. DESIGN: Anti-CII Ab/LPS-induced arthritis was induced in MIF-deficient and wild-type mice. The effects of anti-MIF polyclonal antibody administration on anti-CII Ab-induced arthritis were also evaluated. RESULTS: The expression of MIF protein and mRNA was induced in anti-CII Ab/LPS-induced arthritis joint tissues. Histopathological arthritis scores for synovial inflammation induced by anti-CII Ab/LPS -induced arthritis were significantly decreased in anti-MIF Ab-treated mice and in MIF-deficient mice compared to wild-type mice. In addition, mRNA levels of MMP-13 and MIP-2 in anti-CII Ab/LPS-induced arthritis joint tissues were significantly reduced in MIF-deficient mice compared to wild-type control mice. CONCLUSIONS: These results indicate that MIF plays a critical role in inflammation and joint destruction in the anti-CII Ab/LPS-induced arthritis model in mice, in part via induction of MMP-13 and neutrophil infiltration through the induction of MIP-2.

Xenopus laevis macrophage migration inhibitory factor is essential for axis formation and neural development.

Macrophage migration inhibitory factor (MIF) is an immunoregulatory cytokine involved in both acquired and innate immunity. MIF also has many functions outside the immune system, such as isomerase and oxidoreductase activities and control of cell proliferation. Considering the involvement of MIF in various intra- and extracellular events, we expected that MIF might also be important in vertebrate development. To elucidate the possible role of MIF in developmental processes, we knocked down MIF in embryos of the African clawed frog Xenopus laevis, using MIF-specific morpholino oligomers (MOs). For the synthesis of the MOs, we cloned a cDNA for a Xenopus homolog of MIF. Sequence analysis, determination of the isomerase activity, and x-ray crystallographic analysis revealed that the protein encoded by the cDNA was the ortholog of mammalian MIF. We carried out whole mount in situ hybridization of MIF mRNA and found that MIF was expressed at high levels in the neural tissues of normal embryos. Although early embryogenesis of MO-injected embryos proceeded normally until the gastrula stage, their neurulation was completely inhibited. At the tailbud stage, the MO-injected embryos lacked neural and mesodermal tissues, and also showed severe defects in their head and tail structures. Thus, MIF was found to be essential for axis formation and neural development of Xenopus embryos.

Increased expression of macrophage migration inhibitory factor during fracture healing in rats.

We previously reported that macrophage migration inhibitory factor (MIF) is expressed in osteoblasts in murine calvarial bone, and that MIF upregulates the expression of matrix metalloproteinase (MMP)-13 mRNA in osteoblasts and chondrocytes; however, its pathophysiological functions in bone have not been well understood. In this study, we used a rat femoral fracture model to examine the expression of MIF during the fracture healing process. Semiquantitative reverse transcription-polymerase chain reaction revealed that MIF mRNA was increased throughout the healing process. The level of MIF mRNA reached a maximum at day 4 postfracture, while MMP-13 mRNA became maximal at day 14 postfracture. Immunohistochemical analysis showed that MIF protein was present in the granulation tissues formed at the fracture site on day 4. On days 7 and 10, MIF was detected in the thickened periosteum, in osteoblastic cells that were present within the intramembranously formed bone under the thickened periosteum, and in chondrocytes within the cartilaginous callus. From day 14 to day 28, MIF was present in chondrocytes within the callus, although the level of MIF declined gradually over this period. On days 7 to 14, MMP-13 was also detected in osteoblastic cells within the intramembranously formed bone and in chondrocytes within the cartilaginous callus. The immunoreactivity for MMP-13 within chondrocytes decreased on days 21 and 28. These results suggest the possibility that MIF plays an important role in fracture healing in association with proliferation of stromal cells, and the induction of MMP-13 in osteoblasts or chondrocytes.

Transgene of MIF induces podocyte injury and progressive mesangial sclerosis in the mouse kidney.

BACKGROUND: Recent evidence suggests that macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine that plays a pathogenic role in glomerulonephritis. Renal expression of MIF is up-regulated in infiltrating and intrinsic renal cells, which include glomerular epithelial cells. The aim of the current study was to further clarify the role of MIF produced by podocytes in the process of renal disease. METHODS: We generated transgenic mice carrying a murine MIF cDNA driven by cytomegalovirus enhancer and beta-actin/beta-globin promoter, a hybrid promoter transactivated in podocytes in vivo. RESULTS: MIF expression was markedly up-regulated in podocytes in neonatal and adult transgenic kidneys. A longitudinal study of the MIF transgenic mice demonstrated a progressive matrix increase in mesangium accompanied by collagen IV accumulation, representing no significant glomerular cell hypercellularity. The glomeruli in transgenic kidney were not accompanied by influx of macrophages and T cells at the early stage of disease progression. Although a significant number of the mice showing higher expression of MIF died from renal failure at 8 weeks, most of them survived with significant proteinuria and progressive renal failure. Podocytes of transgenic mice frequently underwent characteristic ultrastructural changes, such as cell flattening, contracted foot processes, and villous transformation. In addition, immunohistochemical expression of synaptopodin, an actin-associated protein distributed in differentiated podocyte foot process, was significantly attenuated in transgenic kidney. CONCLUSION: Our results indicate that podocyte-expressed MIF could induce an injury of podocytes themselves, thereby accelerating the progression of glomerulosclerosis and leading to end-stage renal failure.