Modulation of Melanogenesis by Heme Oxygenase-1 via p53 in Normal Human Melanocytes / 전남의대학술지

As a key regulator of melanogenesis, p53 controls microphthalmia-associated transcription factor (MITF) and tyrosinase expression. The anti-oxidant enzyme heme oxygenase-1 (HO-1) is induced by various forms of cellular stress and diverse oxidative stimuli. However, few studies have examined the role of HO-1 in melanogenesis. Therefore, the aim of this study was to determine the role of HO-1 in melanogenesis and the mechanism underlying this relationship. Cultures of normal human melanocytes were treated with the HO-1 inducer cobalt protoporphyrin (CoPP) or the HO-1 inhibitor zinc protoporphyrin (ZnPP). We then measured the melanin content of the cells. Additional analyses consisted of Western blotting and RT-PCR. The results showed that the cellular melanin content was increased by CoPP and decreased by ZnPP. The Western blot and RT-PCR analyses showed that CoPP increased p53, MITF and tyrosinase levels, and ZnPP reduced all of them. The knockdown of p53 by siRNA transfection was followed by large decreases in the expression levels of p53, MITF and tyrosinase at 3 h of transfection. The presence of CoPP or ZnPP had no significant increased or decreased effects on MITF and tyrosinase levels from 15 h in the siRNA transfectants. Our results suggest that HO-1 modulates melanogenesis in human melanocytes via a p53-dependent pathway.

Modulation of Melanogenesis by Heme Oxygenase-1 via p53 in Normal Human Melanocytes / 전남의대학술지

As a key regulator of melanogenesis, p53 controls microphthalmia-associated transcription factor (MITF) and tyrosinase expression. The anti-oxidant enzyme heme oxygenase-1 (HO-1) is induced by various forms of cellular stress and diverse oxidative stimuli. However, few studies have examined the role of HO-1 in melanogenesis. Therefore, the aim of this study was to determine the role of HO-1 in melanogenesis and the mechanism underlying this relationship. Cultures of normal human melanocytes were treated with the HO-1 inducer cobalt protoporphyrin (CoPP) or the HO-1 inhibitor zinc protoporphyrin (ZnPP). We then measured the melanin content of the cells. Additional analyses consisted of Western blotting and RT-PCR. The results showed that the cellular melanin content was increased by CoPP and decreased by ZnPP. The Western blot and RT-PCR analyses showed that CoPP increased p53, MITF and tyrosinase levels, and ZnPP reduced all of them. The knockdown of p53 by siRNA transfection was followed by large decreases in the expression levels of p53, MITF and tyrosinase at 3 h of transfection. The presence of CoPP or ZnPP had no significant increased or decreased effects on MITF and tyrosinase levels from 15 h in the siRNA transfectants. Our results suggest that HO-1 modulates melanogenesis in human melanocytes via a p53-dependent pathway.

Hemeoxgenase-1 mediates the protective effect of hyperbaric oxygen preconditioning against the brain edema after experimental hemorrhage in rats / 中华急诊医学杂志

Objective To investigate the role of Heme oxygenase-1 in the effect of hyperbaric oxygen preconditioning (HBOP) against the brain edema formation after experimental intracerebral hemorrhage in rats.Methods The study was carried out by animal experiment in two steps by using 54 Spradgue-Dawley rats weighting from 300-350 g.In the first step,rats were treated with HBOP (HBOP group,n =3) or with sham pre-conditioning (Sham pre-conditioning group,n =3).All the rats were sacrificed 24 h after the preconditioning,and basal ganglion of brain tissue was taken for detect HO-1 level by using western blot analysis.In the second step,rats were divided into 4 groups (n =12 in each group):HBOP +ZnPP group,in which rats had a micro-pump intra-peritoneally implanted containing a specific HO-1 inhibitor ZnPPⅨ (Zinc protoporphyrin IX,0.01 mg/kg),Sham pre-conditioning + Znpp group,HBOP + DMSO group,in which rats with a intra-peritoneal micro-pump containing 2 mL Dimethyl sulfoxide (DMSO,a solvent vehicle) and Sham pre-conditioning + DMSO group before HBOP.At 24 hours after the pre-conditioning,rats received an infusion of 100 μL autologous blood into the caudate nucleus to form a simulated intracerebrum hemorrhage (ICH),and were sacrificed 72 h later for brain water content measurements.All data were analyzed by using Stata 7.0 software and statistical analyses were carried out by two-tailed Student t test.Results Compared with the Sham pre-conditioning group,the HBOP group had significant higher level of HO-1.Compared with the Sham pre-conditioning + DMSO group,the HBOP + DMSO group had a significant lower level of water content in the ipsilateral basal ganglion [(81.4 ± 0.9) ％ vs.(82.6 ± 0.8) ％ (P ＜ 0.05)],however,peritoneal infusion of ZnPP Ⅸ before HBOP abolished HBOP-induced protection against brain edema formation after experimental ICH [(82.8 ± 0.9) ％ vs.(82.6 ± 0.7) ％ (P ＞ 0.05)].Conclusions Hyperbaric oxygen preconditioning attenuate brain edema formation after experimental ICH in rats,and this protection is attributed to the activation of HO-1.

The effects of Zinc Protoporphyrin and Heme on the expression of HO-1 in cochlear and the change of auditory brainstem response on diffuse traumatic brain injury model of rats / 中国基层医药

Objective To explore the effects of Zinc Protoporphyrin and Heme on the expression of HO-1 in cochlear and the change of auditory brainstem response on diffuse traumatic brain injury model of rats.Methods Diffuse traumatic brain injury model of rats were established and randomly divided into thirteen groups.Then auditory brainstem response examination,light microscope,immunohistochemistry technique were used to evaluate the change of auditory brainstem response and the expression of HO-1 in cochlear.Results The differences of auditory brainstem response threshold and latency of wave between the experimental and the normal control group were obvious(P＜0.05).The expression of HO-1 in the control group was normal,whereas there were obvious changes of inner ear HO-1 expression in the traumatic groups.The grey value of HO-1 expression in trauma group,Znpp group and heme group was significantly associated with auditory function change(P＜0.05).Conclusion There were influence of Zinc Protoporphyrin and Hemeon the inner ear HO-1 expression and the change of auditory brainstem response with diffuse traumatic brain injury model of rats.The protective effect of heme on auditory function may be associated with the increased expression of HO-1.

Assessment of Iron Parameters in Children with Acute Infectious Disease / 임상소아혈액종양

BACKGROUND: As some parameters reflecting iron status were known to change with infection or inflammation, we examined the changes of these parameters in children with minor illnesses.METHODS: Hematologic tests were done in 42 young children with acute infection. Iron deficiency anemia (IDA) was defined as having Hb less than age-matched normal range, MCH <27 pg, and either Tfsat (transferrin saturation) <10% or TIBC >360 microg/dL. Iron deficiency (ID) was defined as having Hb equal or more than age matched normal low limit with MCH <27 pg, and either Tfsat <10% or TIBC >360 microg/dL. The others were classified as normal control (NC).RESULTS: The proportion of IDA, ID and NC were 16.6% (7/42), 33.3% (14/42) and 50.0% (21/42), respectively. Comparisons of means of Hb, MCV, MCH, and RDW between groups showed statistical difference in general, while levels of iron, ferritin and hs-CRP showed no statistical difference. Mean blood levels of zinc protoporphyrin (ZnPP) of IDA, ID and NC were 72.21 microg/dL, 57.02 microg/dL, and 45.62 microg/dL, respectively, but the difference was significant only between IDA and NC. ZnPP was inversely correlated with MCV (r=-0.518, P<0.01) and RDW (r=-0.640, P<0.01), but not with hs-CRP or ferritin.CONCLUSION: Combination of RBC indices with newly controlled Tfsat or TIBC can be available for an iron status assessment in children with minor infections. ZnPP levels in blood reflect some aspect of iron status, while ferritin and iron do not reflect it.

Assessment of Iron Parameters in Children with Acute Infectious Disease / 임상소아혈액종양

BACKGROUND: As some parameters reflecting iron status were known to change with infection or inflammation, we examined the changes of these parameters in children with minor illnesses. METHODS: Hematologic tests were done in 42 young children with acute infection. Iron deficiency anemia (IDA) was defined as having Hb less than age-matched normal range, MCH 360 microg/dL. Iron deficiency (ID) was defined as having Hb equal or more than age matched normal low limit with MCH 360 microg/dL. The others were classified as normal control (NC). RESULTS: The proportion of IDA, ID and NC were 16.6% (7/42), 33.3% (14/42) and 50.0% (21/42), respectively. Comparisons of means of Hb, MCV, MCH, and RDW between groups showed statistical difference in general, while levels of iron, ferritin and hs-CRP showed no statistical difference. Mean blood levels of zinc protoporphyrin (ZnPP) of IDA, ID and NC were 72.21 microg/dL, 57.02 microg/dL, and 45.62 microg/dL, respectively, but the difference was significant only between IDA and NC. ZnPP was inversely correlated with MCV (r=-0.518, P<0.01) and RDW (r=-0.640, P<0.01), but not with hs-CRP or ferritin. CONCLUSION: Combination of RBC indices with newly controlled Tfsat or TIBC can be available for an iron status assessment in children with minor infections. ZnPP levels in blood reflect some aspect of iron status, while ferritin and iron do not reflect it.

Occupational Health Management in the Lead Industry: The Korean Experience

In 1967, the problem of occupational lead exposure came to public attention in Korea. Since then, regular progress has been made in lowering workplace lead exposures, instituting new workplace controls, and implementing health examinations of exposed workers. Past serious lead poisoning episodes made it possible to introduce biological monitoring programs on a voluntary basis in high-lead-exposure facilities in Korea. Industry-specific occupational health services for lead workers in Korea during the last 22 years can be categorized into three phases. During the first phase (1988-1993), efforts were directed at increasing awareness among workers about the hazards of lead exposure, biological monitoring of blood zinc protoporphyrin began, and a respiratory protection program was introduced. During the second phase (1994-1997), a computerized health management system for lead workers was developed, blood-lead measurement was added to biologic monitoring, and engineering controls were introduced in the workplace to lower air-lead levels to comply with air-lead regulations. Finally, during the third phase (1998-present), a new biomarker, bone-lead measurement by X-ray fluorescence, was introduced. Bone-lead measurement proved to be useful for assessing body burden and to demonstrate past lead exposure in retired workers. Occupational health service practice for lead workers, including the industry-specific group occupational health system, has brought considerable success in the prevention of lead poisoning and in reducing the lead burden in Korean lead workers during the last several decades. The successful achievement of prevention of lead poisoning in Korea was a result of the combined efforts of lead workers, employers, relevant government agencies, and academic institutes.

Effects of zinc protoporphyrin on the colonic interstitial cells of Cajal and dysfunction in diabetic rats / 中华消化杂志

Objective To assess the effects of zinc protoporphyrin (ZnPP), an inhibitor of the heme oxygenase (HO), on the colonic interstitial cells of Cajal (ICC) of diabetic rats with colonic slow transit. Methods Diabetes mellitus (DM) model was induced by intraperitoneal injection of streptozotocin (STZ) in Sprague-Dawley rats. Twenty four successfully established DM rats were selected, and 16 healthy rats were served as controls. Six weeks later, gastrointestional (GI) dysfunction was observed by charcoal propulsion experiment in 8 DM rats and 8 controls. The rest rats in DM group were divided into 2 groups: DM rats intraperitoneal injected with PBS (n=8) or with 10 μmol/kg of ZnPP (n = 8) every other day for 3 weeks. The rats in control group (n = 8) were intraperitoneally injected with PBS. The levels of HO and c-kit (the special receptor of ICC) expression were detected by Western blotting. The distribution of ICC was observed by immunohistochemistry and the area of c-kit positive cells was counted. Results The GI propulsion rate in DM rats interfered with PBS was significantly declined compared to that in the controls (63.0%± 1.2% vs 71.8%±2.0%, P<0.05). But it was improved in DM rats interfered with ZnPP (72.5± 2.6%, P<0.05), which showed no significant differentee with that in control group (P>0.05). The expression of HO-1 in close and distant colon of DM rats interfered with ZnPP was decreased (P< 0.05). The expression of HO-2 in close colon and the area of c-kit positive cells of DM rats interfered with PBS was reduced compared with that in controls (P<0.05), but both were improved in DM rats interfered with ZnPP (P<0. 05). Conclusion Administration of ZnPP might be able to protect ICC by its blockage of HO-1 in DM rats with gastrointestinal dysfunction.

The Relationship between Psychosocial Distress and Lead Exposure Indices in Lead Workers / 대한산업의학회지

OBJECTIVES: This study was carried out to assess psychosocial distress of lead workers and to examine the relationship between lead exposure indices and psychosocial distress. METHODS: The study design was cross-sectional and research subjects were 234 lead workers in primary smelting industry. General characteristics, job characteristics and social support were obtained by self-administered questionnaire and history taking. Psychosocial distress was measured using PWI(Psychosocial Well-being Index), a 45-item self-administered instrument. Blood lead(PbB), zinc protoporphyrin(ZPP), -aminolevulinic acid in urine(ALAU) were selected as indicators of lead exposure. RESULTS: There was significant difference in PWI according to lead exposure level and job characteristics. The results of correlation analysis showed that PWI was significantly correlated with PbB(r=0.203, P=0.002). CONCLUSIONS: Our results supported the association between lead exposure and psychosocial distress. The inclusion of psychosocial distress measurement as a special health examination for lead workers was highly recommended for the effective health management.

Different Effect of Blood Lead on Zinc Protoporphyrin by Gender in Korean Lead Workers / 예방의학회지

OBJECTIVES: To evaluate whether a relation between blood lead and zinc proto porphyrin(ZPP) was modified by gender in Korean lead workers. METHODS: A cross-sectional study was conducted with 1,304 male and 101 female subjects in 1997. The relation between blood lead and ZPP were evaluated with linear, exponential, and quadratic models. Then, the different effect of gender on the relation was examined by adding the interaction terms in the each model. RESULTS: Mean+/-SD of blood lead and ZPP level was different between male(27.7+/-10 microgram /dl and 51.3+/-23.4 microgram/dl) and female subjects(22.5+/-9.2 microgram/dl and 78.7+/-38.6 microgram/dl). After adjusting for possible confounders, the effect modification by gender was significant in linear(beta=1.119, p<0.001), exponential(beta=Exp(0.008), p<0.05), and quadratic model(beta= 1.388, p<0.001). In separate analysis, a quadratic relation between blood lead and ZPP was shown in male lead workers(beta=0.036, p<0.001), but an exponential relation in female lead workers(n=Exp(0.029), p<0.001). CONCLUSION: Our data showed that the increasing rate of ZPP in female were always higher than in male lead workers, suggesting that females were more susceptible to occupational lead exposure than males.

Occupational Lead Exposure of Storage Battery Industry Workers in Korea / 대한산업의학회지

In order to investigate the level of lead absorption of lead workers and to evaluate the effect of blood lead on blood zinc protoporphyrin (ZPP) and prevalence of lead related symptoms, 1,782 lead workers(male: 1,506, female: 276) from 8 storage battery industries were studied. Selected variables as indices of lead exposure were blood lead, blood ZPP, and hemoglobin (HB). Fifteen questionnaires of lead related symptoms were provided to all lead workers and filled up by themselves and confirmed by medical doctors. Personal variables such as age, work duration, smoking and drinking habits were also collected. The results were follows : 1. While the mean blood lead of lead workers of all lead companies was 31.0+/-3.0 ug/100ml (male: 31.5+/-2.9 ug/100ml, female: 27.9+/-3.3 ug/100m1), the mean blood ZPP of all lead workers was 66.7+/-4.1 ug/100ml (male: 59.6+/-3.3, female: 105.3+/-3.0 ug/100ml). The mean hemoglobin of male lead workers was 15.7+/-.3 gm/100ml and that of female lead workers was 13.0+/-.3 gm/100ml. 2. The percentage of lead workers whose blood lead was over 60.0 ug/100m1 and 40.0-59.9 ug/100ml was 2.81 % and 19.08 %, respectively. On the other hand, the percentage of lead workers whose blood ZPP was over 150 ug/100ml and 100-149 ug/100ml was 5.89 % and 8.31 %, respectively. 3. The slopes of simple linear regression of blood lead (independent variable) and blood ZPP in female lead workers was significantly steeper than that of male lead workers. The slope of storage battery industries with better working condition in terms of low air concentration of lead were less steeper than those with poor working condition with high mean air concentration of lead. 4. Stepwise multiple regression analysis, using overall symptom prevalence as a dependent variables, blood lead, blood ZPP, hemoglobin, age, work duration, drinking and smoking habits as independent variables, indicated that only drinking habit and age were significantly contributed to the dependent variable.

A Study on the Lead Exposure of Workers in Secondary Smelting and Litharge Making Industries / 대한산업의학회지

Two hundred and six male lead workers (86 lead workers from secondary smelting industries and 120 lead workers from litharge making industries) and 212 office workers who were not exposed to lead occupationally were studied to investigate the effect of lead on the health of lead workers in high risk operation to lead. Blood lead (PbB), zinc protoporphyrin in whole blood (ZPP), delta-aminolevulinic acid in urine (ALAU), Hematocrit (Hct) and hemoglobin (Hb) were selected as an index of lead exposure. Questionnaires of 15 lead related symptoms were provided to all study subject and filled up by themselves and reconfirmed the symptom answers by interviewing medical doctor. While the mean value of PbB, ZPP and ALAU of lead workers in secondary smelting industries were 62.7+/-14.6 microgram/dl, 103.1+/-60.5 microgram/dl and 7.4+/-10.3 mg/liter, those of lead workers in litharge making industries were 58.8+/-14.1 microgram/dl, 74.2+/-45.2 microgram/dl and 5.3+/- 7.9 mg/liter respectively, and there were statistically significant difference of mean values between two groups. Simple linear regression analysis of PBB on ZPP and ALAU shoved the steeper slope in secondary smelting industries than litharge making industries. Higher symptom prevalence rates of lead exposed group were observed in lead colic related symptom (S4) and neuromuscular symptoms compared with non-exposed workers. The prevalence of neuromuscular symptoms only showed dose-response relationship by the increase of PBB and ZPP. But more statistical significances were observed in neuromuscular symptoms by the increase of PBB than ZPP. On stepwise multiple regression using total symptom score as a dependent variable and PBB, ZPP, ALAU, Hct, Hb, age and work duration as a independent variables only ZPP and age contributed to the lead related symptoms.

Effects of Long-term Consumption of Purified Water on Lead Accumulation in Organs of Rats / 环境与健康杂志

Objective To understand whether long term consumption of purified water can cause lead accumulation and enhance lead toxicity in the rats with chronic lead exposure. Methods 104 male SD weaned rats were randomly divided into eight groups,tap water,purified water,tap water plus lead (lead acetate,Pb2+: 50 mg/L ),purified water plus lead (Pb2+: 50 mg /L),tap water plus lead (Pb2+: 200 mg/L ),purified water plus lead (Pb2+: 200 mg/L),tap water plus lead (Pb2+: 800 mg/L),purified water plus lead (Pb2+: 800 mg/L). All were fed with normal food and kept in the same environmental conditions. The blood samples were collected after 4,6,8,10,24 and 28 weeks of lead exposure. The brain,heart,liver,kidney,bone were sampled at the experimental endpoint and the lead concentration was determined with graphite furnace atomic absorption spectrometric method,zinc protoporphyrin (ZPP) level was measured by using surface fluorescence method. Results At the same lead exposure level,no difference of blood lead level was observed between the groups of drinking purified water and tap water,however,the lead level in the organs tissue,including brain,heart,liver,kidney,bone,was significantly higher in the group drinking purified water compared with drinking tap water. The blood ZPP level in rats drinking purified water was also higher than the rats drinking tap water,the significant difference were occurred at low lead level exposure (P