| 1. |
- Ren, Zhenjing, et al.
(författare)
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Tetratricopeptide-containing SMALL KERNEL 11 is essential for the assembly of cytochrome c oxidase in maize mitochondria
- 2023
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Ingår i: Plant Physiology. - : Oxford University Press (OUP). - 0032-0889 .- 1532-2548. ; 192:1, s. 170-187
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Tidskriftsartikel (refereegranskat)abstract
- Assembly of the functional complexes of the mitochondrial respiratory chain requires sophisticated and efficient regulatory mechanisms. In plants, the subunit composition and assembly factors involved in the biogenesis of cytochrome c oxidase (complex IV) are substantially less defined than in mammals and yeast. In this study, we cloned maize (Zea mays) Small kernel 11 (Smk11) via map-based cloning. Smk11 encodes a mitochondria-localized tetratricopeptide repeat protein. Disruption of Smk11 severely affected the assembly and activity of mitochondrial complex IV, leading to delayed plant growth and seed development. Protein interactions studies revealed that SMK11 might interact with four putative complex IV assembly factors, Inner membrane peptidase 1A (ZmIMP1A), MYB domain protein 3R3 (ZmMYB3R-3), cytochrome c oxidase 23 (ZmCOX23), and mitochondrial ferredoxin 1 (ZmMFDX1), among which ZmMFDX1 might interact with subunits ZmCOX6a and ZmCOX-X1; ZmMYB3R-3 might also interact with ZmCOX6a. The mutation of SMK11 perturbed the normal assembly of these subunits, leading to the inactivation of complex IV. The results of this study revealed that SMK11 serves as an accessory assembly factor required for the normal assembly of subunits into complex IV, which will accelerate the elucidation of the assembly of complex IV in plant mitochondria.
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| 2. |
- Chen, Xiao, et al.
(författare)
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The association between cumulative cadmium intake and osteoporosis and risk of fracture in a Chinese population
- 2019
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Ingår i: Journal of Exposure Science and Environmental Epidemiology. - : Springer. - 1559-0631 .- 1559-064X. ; 29:3, s. 435-443
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Tidskriftsartikel (refereegranskat)abstract
- Bone is one of the target organs for cadmium toxicity. However, few studies have shown the association between cumulative cadmium intake and prevalence of osteoporosis and bone fracture. In the present study, we evaluated the association between cumulative cadmium intake and osteoporosis and risk of fracture in a Chinese population. A total of 790 subjects (488 women and 302 men) living in a control area and two cadmium-polluted areas were included. The cumulative cadmium intake was estimated by a food survey. The bone mineral density was determined by using single-photon absorptiometry. The cumulative cadmium intakes were 0.48, 2.14, and 11.00 g for men, and 0.42, 2.11, and 11.12 g in women in control, and moderately and heavily polluted areas, respectively. In women, the odds ratios (ORs) of subjects with a cadmium intake between 2.21 and 10.63 g and >10.63 g were 1.30 (95% CI: 0.58-2.94) and 2.36 (95% CI: 1.14-5.16), compared with those with a cadmium intake < 0.58 g after adjusting to the confounders for osteoporosis. The ORs of subjects with a cadmium intake >10.63 g were 2.34 (95% CI: 1.23-4.38) for all of the women and 2.62 (95% CI: 1.02-5.58) in women ≥ 60 years old, compared with those with a cadmium intake <10.63 g after adjusting to the confounders for bone fractures. In men, similar trends were observed, but no statistical significance was found. In addition, those subjects with renal tubular dysfunction showed high risk of bone fracture. Our results indicate that a high level of cumulative cadmium intake is associated with an increased rate of osteoporosis and fractures among women.
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| 3. |
- Chen, Xiao, et al.
(författare)
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The association between dietary cadmium exposure and renal dysfunction - the benchmark dose estimation of reference levels : the ChinaCad study
- 2018
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Ingår i: Journal of Applied Toxicology. - : John Wiley & Sons. - 0260-437X .- 1099-1263. ; 38:10, s. 1365-1373
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Tidskriftsartikel (refereegranskat)abstract
- The tolerable dietary intake of cadmium was recommended at provisional tolerable monthly intake of 25gkg(-1) body weight. However, several studies indicated that this tolerable level should be re-evaluated for sufficient health protection. In this study, we show the reference levels of dietary cadmium intake for renal dysfunction by using a benchmark dose (BMD) approach. A total of 790 subjects (302 men and 488 women) living in control and cadmium-polluted areas were included. The dietary cadmium intake was estimated by a food survey. Blood cadmium, urinary cadmium and renal function markers (microalbuminuria, N-acetyl--d-glucosaminidase [NAG] and its isoform B [NAGB], (2)-microglobulin and retinol binding protein) in urine were measured. We calculated the 95% lower confidence bounds of BMD (BMDLs) of cumulative cadmium intake. In control and two polluted areas, the median cumulative cadmium intake was 0.5, 2.1 and 11.1g. The odds ratio of the intermediate (1.0-3.0g), second highest (3.0-11.0g) and the highest cumulative cadmium intake (>11.0g) compared with the lowest cumulative cadmium intake (<1.0g) were 2.8 (95% CI: 1.4-5.8), 8.1 (95% CI: 3.8-17.2) and 11.4 (95% CI: 6.5-26.4) for urinary NAG and 6.6 (95% CI: 3.2-13.8), 14.8 (95% CI: 6.8-32.2) and 22.5 (95% CI: 10.7-47.5) for urinary NAGB. The BMDLs of cumulative cadmium intake were 1.1-1.2g (benchmark response [BMR]=5%) for urinary NAG, and were 0.7-0.9g (BMR=5%) for urinary NAGB, and were 1.3-1.4g (BMR=5%) for urinary (2)-microglobulin. The BMDLs of cumulative cadmium intake in a Chinese population were lower than the critical standard previously reported. Further evaluations are needed for sufficient health protection. Several studies indicated that the tolerable dietary intake of cadmium should be re-evaluated for sufficient health protection. In this study, we show the reference levels of dietary cadmium intake for renal dysfunction by using benchmark dose (BMD) approach. The lowest BMD lower bound confidence limits of cumulative cadmium intake were 0.7-0.9g (benchmark response=5%). The BMD lower bound confidence limits of cumulative cadmium intake were lower than the critical standard previously reported. Further evaluations are needed for sufficient health protection.
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| 4. |
- Chen, Xiao, et al.
(författare)
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The association between renal tubular dysfunction and zinc level in a Chinese population environmentally exposed to cadmium
- 2018
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Ingår i: Biological Trace Element Research. - : Humana Press. - 0163-4984 .- 1559-0720. ; 186:1, s. 114-121
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Tidskriftsartikel (refereegranskat)abstract
- Microglobulin (UBMG) were measured. The median UCd, BCd, SZn, and HZn were 2.8 and 13.6 μg/g cr, 1.3 and 12.2 μg/L, 1.31 and 1.12 mg/L, and 0.14 and 0.12 mg/g in subjects living in control and polluted areas. The UBMG level of subjects living in the polluted area was significantly higher than that of the control (0.27 vs 0.11 mg/g cr, p < 0.01). SZn, HZn, and Zn/Cd ratios were negatively correlated with UBMG (p < 0.05 or 0.01). Subjects with high SZn concentrations (≥ 1.62 mg/L) had reduced risks of elevated UBMG [(odds ratio (OR) = 0.26, 95% confidence interval (CI) 0.07-0.99)] after controlling for multiple covariates compared with those with lower zinc levels. A similar result was observed in subjects with high HZn (OR = 0.09, 95% CI 0.02-0.48). The ORs of the second, third, and fourth quartiles of Zn/Cd ratio were 0.40 (95% CI 0.19-0.84), 0.14 (95% CI 0.06-0.37), and 0.01 (95% CI 0.02-0.18) for renal dysfunction compared with those of the first quartile, respectively. For those subjects with high level of UCd, high level of SZn and HZn also had reduced risks of elevated UBMG. The results of the present study show that high zinc body burden is associated with a decrease risk of renal tubular dysfunction induced by cadmium. Zinc nutritional status should be considered in evaluating cadmium-induced renal damage.
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| 5. |
- Fan, Kaijian, et al.
(författare)
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The pentatricopeptide repeat protein EMP603 is required for the splicing of mitochondrial Nad1 intron 2 and seed development in maize
- 2021
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Ingår i: Journal of Experimental Botany. - : Oxford University Press (OUP). - 0022-0957 .- 1460-2431. ; 72:20, s. 6933-6948
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Tidskriftsartikel (refereegranskat)abstract
- Intron splicing is an essential event in post-transcriptional RNA processing in plant mitochondria, which requires the participation of diverse nuclear-encoded splicing factors. However, it is presently unclear how these proteins cooperatively take part in the splicing of specific introns. In this study, we characterized a nuclear-encoded mitochondrial P-type pentatricopeptide repeat (PPR) protein named EMP603. This protein is essential for splicing of intron 2 in the Nad1 gene and interacts with the mitochondria-localized DEAD-box RNA helicase PMH2-5140, the RAD52-like proteins ODB1-0814 and ODB1-5061, and the CRM domain-containing protein Zm-mCSF1. Further study revealed that the N-terminal region of EMP603 interacts with the DEAD-box of PMH2-5140, the CRM domain of Zm-mCSF1, and OBD1-5061, but not with OBD1-0814, whereas the PPR domain of EMP603 can interact with ODB1-0814, ODB1-5061, and PMH2-5140, but not with Zm-mCSF1. Defects in EMP603 severely disrupt the assembly and activity of mitochondrial complex I, leading to impaired mitochondrial function, and delayed seed development. The interactions revealed between EMP603 and PMH2-5140, ODB1-0814, ODB1-5061, and Zm-mCSF1 indicate a possible involvement of a dynamic 'spliceosome-like' complex in intron splicing, and may accelerate the elucidation of the intron splicing mechanism in plant mitochondria.
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| 6. |
- Jin, Taiyi, et al.
(författare)
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Osteoporosis and renal dysfunction in a general population exposed to cadmium in China.
- 2004
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Ingår i: Environmental research. - : Elsevier BV. - 0013-9351. ; 96:3, s. 353-9
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Tidskriftsartikel (refereegranskat)abstract
- Osteoporosis is a common metabolic disease characterized by low bone mass and microarchitectural deterioration of bone tissue. Many factors are involved in the occurrence of osteoporosis. Cadmium can cause both osteomalacia and osteoporosis and these effects have long been investigated through various epidemiological or experimental studies. The present study examines a possible relationship between cadmium nephropathy and its effects on the skeleton in populations living in a polluted area in southeast China. Monophoton absorptiometry was used to measure bone mineral density in the population and the Z score (the number of SD from the difference between the measured bone density of the individual and the group mean value for sex- and age-matched controls) was introduced to define osteoporosis (Z score < -2). Osteoporosis caused by cadmium exposure was demonstrated in this study on a general population environmentally exposed to cadmium in China. It was found that there were significant differences in the prevalence of osteoporosis among the different urinary cadmium groups (chi2 = 18.84, P = 0.0008). The linear trend test gave chi2 = 16.281, P = 0.00005. There was a dose-response relationship between cadmium exposure (urinary cadmium) and prevalence of osteoporosis. Of 31 subjects with osteoporosis, 23 subjects were suffering from renal dysfunction. The prevalence of renal dysfunction (74.19%) was significantly higher than that in those without osteoporosis (chi2 = 16.53, P < 0.001). Stratum analysis was performed to further assess the relationship between bone damage and renal impairment caused by cadmium. There was a significant difference between those with and without tubular damage (chi2 = 19.92, P = 0.000) but not in those with and without glomerular damage (chi2 = 0.08, P = 0.114). This showed that glomerular dysfunction plays a smaller role than tubular dysfunction in the causation of bone damage. It was found that the prevalence of osteoporosis increases with increasing values of parameters of tubular damage. Osteoporosis caused by cadmium is thus related to kidney dysfunction and especially to tubular damage and its severity but not to glomerular damage. The present study has thus demonstrated the combined adverse effects (osteoporosis and renal dysfunction) caused by environmental exposure to cadmium for the first time in Asia outside the endemic area in Japan.
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| 7. |
- Shi, Peng, et al.
(författare)
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Age- and gender-specific trends in respiratory outpatient visits and diagnoses at a tertiary pediatric hospital in China : a 10-year retrospective study
- 2020
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Ingår i: BMC Pediatrics. - : BioMed Central. - 1471-2431. ; 20:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Respiratory infections are one of three leading causes of childhood mortality, and worldwide increase and recent plateau in childhood asthma has been reported. However, data on trends of respiratory diseases over long period of time is limited. This study aimed to determine the trends of respiratory disease outpatient visits (ROVs) and diagnoses (RODs) in one of the largest children's teaching hospitals in China between 2009 and 2018.METHODS: A retrospective study based on routine administrative data was designed and implemented according to the RECORD statement. Demographic details and diagnoses of the outpatients < 18 years visiting the respiratory department of the hospital were extracted from the Hospital Information System. Age- and gender-specific trends were illustrated by calculating average annual growth rate (AAGR) for ROVs and comparing change of proportion for different RODs over time.RESULTS: There were 698,054 ROVs from 285,574 children (40.4% female). AAGR of ROVs was 15.2%. Children aged 4 to < 7 years had a faster increase than other age groups. Bronchitis (27.6%), pneumonia (18.5%), pneumonia affecting other systems (18.4%), asthma and status asthmaticus (10.7%), and vasomotor and allergic rhinitis (9.2%) accounted for 84.4% of all RODs. The proportion of bronchitis decreased across years, with the concomitant increasing trend in the proportion of pneumonia. Age-specific trend in diagnoses showed greater proportion of asthma in all visits for the children aged 7 to < 18 years than younger children. Gender-specific trend in diagnoses showed the proportion of asthma was greater for males but the AAGR was greater for females.CONCLUSION: The persistent upward trend in ROVs was observed among children at different ages and a gender difference was also seen. In contrast to what has been reported, burden of asthma and allergies diseases continues to increase locally.
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| 8. |
- Zhu, Guoying, et al.
(författare)
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Environmental cadmium exposure and forearm bone density.
- 2004
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Ingår i: Biometals : an international journal on the role of metal ions in biology, biochemistry, and medicine. - : Kluwer Academic Publishers. - 0966-0844 .- 1572-8773. ; 17:5, s. 499-503
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Tidskriftsartikel (refereegranskat)abstract
- Environmental exposure to cadmium may give rise to osteomalacia combined with renal dysfunction, so called 'Itai-Itai disease', which was endemic in the heavily polluted area in Japan. The main focus of this study was to investigate whether environmental exposure to cadmium is associated with low bone mass in a population living near a smelter. A total of 790 persons (302 males and 488 females), who were all over 35 years old and resided in areas near a lead, zinc and cadmium smelter and in a control area in southeast China, completed a questionnaire, and bone mineral density was measured by SPA-4 single photon absorptiometry at the radius and ulna. Cadmium content of urine was determined by graphite-furnace atomic absorption spectrophotometry as a measure of dose. The present study shows that forearm bone densities were negatively correlated with urinary cadmium excretion (p < 0.001) and forearm bone density decreased linearly with age (p < 0.001) and urinary cadmium (p < 0.01), suggesting a dose-effect relationship between cadmium dose and bone mineral density. Based on the World Health Organization criteria, (bone mineral density < -2.5 SDs below the normal young adult), the prevalence of osteoporosis in women increased from 34.0% in the control area to 51.9% in the heavily polluted area (p < 0.01) among subjects over 50 years old, and the odds ratio value was 2.09 (95% CI: 1.08-4.03) for the highly polluted area compared with the control area. A striking observation in the study was a marked increase of the prevalence of fracture in the cadmium-polluted area in both sexes. It was concluded that environmental exposure to cadmium is associated with an increased loss of bone mineral density in both gender, leading to osteoporosis and increased risk of fractures, especially in the elderly and in females.
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