Lower serum zinc levels are associated with unhealthy metabolic status in normal-weight adults: The 2010 Korea National Health and Nutrition Examination Survey

AIM

This study investigated whether serum zinc concentration is associated with glucose tolerance, insulin resistance and metabolic health status in Korean adults.

METHODS

Subjects with available serum zinc levels were recruited from the fifth Korea National Health and Nutrition Examination Survey (KNHANESV) cohort. Those in the highest quartile on homoeostasis model assessment for insulin resistance (HOMA-IR) and with a body mass index (BMI) of 18.5-25kg/m(2) were classified as metabolically obese and normal weight (MONW).

RESULTS

A total of 1813 subjects with a mean age of 45.2±0.5 years and a mean BMI of 24.01±0.11kg/m(2) were enrolled. Those in the lower serum zinc quartiles exhibited higher levels of fasting blood glucose and insulin resistance indices compared with those in the higher quartiles. However, these associations were positive only in normal-weight subjects. Those categorized as MONW exhibited significantly lower serum zinc levels than the metabolically healthy and normal weight (MHNW) subjects (131.6±3.0μg/dL vs 141.7±2.8μg/dL, respectively; P=0.0026), whereas serum zinc levels did not differ according to metabolic health in obese subjects. The odds ratio for being categorized as MONW was 4.12 (95% CI: 1.75, 9.72) among those in the lowest serum zinc quartile compared with those in the highest quartile even after adjusting for possible confounding factors.

CONCLUSION

Lower serum zinc levels were associated with unhealthy metabolic status in normal-weight adults. Further prospective studies are required to define the role of zinc in metabolic health.

Mitochondrial DNA genomes organization and phylogenetic relationships analysis of eight anemonefishes (pomacentridae: amphiprioninae)

Anemonefishes (Pomacentridae Amphiprioninae) are a group of 30 valid coral reef fish species with their phylogenetic relationships still under debate. The eight available mitogenomes of anemonefishes were used to reconstruct the molecular phylogenetic tree; six were obtained from this study (Amphiprion clarkii, A. frenatus, A. percula, A. perideraion, A. polymnus and Premnas biaculeatus) and two from GenBank (A. bicinctus and A. ocellaris). The seven Amphiprion species represent all four subgenera and P. biaculeatus is the only species from Premnas. The eight mitogenomes of anemonefishes encoded 13 protein-coding genes, two rRNA genes, 22 tRNA genes and two main non-coding regions, with the gene arrangement and translation direction basically identical to other typical vertebrate mitogenomes. Among the 13 protein-coding genes, A. ocellaris (AP006017) and A. percula (KJ174497) had the same length in ND5 with 1,866 bp, which were three nucleotides less than the other six anemonefishes. Both structures of ND5, however, could translate to amino acid successfully. Only four mitogenomes had the tandem repeats in D-loop; the tandem repeats were located in downstream after Conserved Sequence Block rather than the upstream and repeated in a simply way. The phylogenetic utility was tested with Bayesian and Maximum Likelihood methods using all 13 protein-coding genes. The results strongly supported that the subfamily Amphiprioninae was monophyletic and P. biaculeatus should be assigned to the genus Amphiprion. Premnas biaculeatus with the percula complex were revealed to be the ancient anemonefish species. The tree forms of ND1, COIII, ND4, Cytb, Cytb+12S rRNA, Cytb+COI and Cytb+COI+12S rRNA were similar to that 13 protein-coding genes, therefore, we suggested that the suitable single mitochondrial gene for phylogenetic analysis of anemonefishes maybe Cytb. Additional mitogenomes of anemonefishes with a combination of nuclear markers will be useful to substantiate these conclusions in future studies.

Nanotoxicity of silver nanoparticles to red blood cells: size dependent adsorption, uptake, and hemolytic activity

Silver nanoparticles (AgNPs) are increasingly being used as antimicrobial agents and drug carriers in biomedical fields. However, toxicological information on their effects on red blood cells (RBCs) and the mechanisms involved remain sparse. In this article, we examined the size dependent nanotoxicity of AgNPs using three different characteristic sizes of 15 nm (AgNPs15), 50 nm (AgNPs50), and 100 nm (AgNPs100) against fish RBCs. Optical microscopy and transmission electron microscopy observations showed that AgNPs exhibited a size effect on their adsorption and uptake by RBCs. The middle sized AgNPs50, compared with the smaller or bigger ones, showed the highest level of adsorption and uptake by the RBCs, suggesting an optimal size of ∼50 nm for passive uptake by RBCs. The toxic effects determined based on the hemolysis, membrane injury, lipid peroxidation, and antioxidant enzyme production were fairly size and dose dependent. In particular, the smallest sized AgNPs15 displayed a greater ability to induce hemolysis and membrane damage than AgNPs50 and AgNPs100. Such cytotoxicity induced by AgNPs should be attributed to the direct interaction of the nanoparticle with the RBCs, resulting in the production of oxidative stress, membrane injury, and subsequently hemolysis. Overall, the results suggest that particle size is a critical factor influencing the interaction between AgNPs and the RBCs.

Interleukin-37 gene variants segregated anciently coexist during hominid evolution

IL37 is a member of IL-1 cytokine family but conveys anti-inflammatory functions. The biological characteristic and genetic heterogeneity of IL37 are not fully understood yet. Here using the whole-genome sequencing data from 1000 Genomes Project, we performed population and evolutionary genetic analysis of human IL37 gene. First, 2184 IL37 gene sequences from different human populations were retrieved. The IL37 protein sequences were inferred from the coding DNA sequences and multiple species alignment was made. Then, the phylogenetic tree of IL37 was built and dN/dS ratios were calculated for each evolutionary branch, the classic McDonald and Kreitman test was also performed. Next, we conducted intraspecific evolutionary genetic analysis and built the genealogy network of 116 unique IL37 haplotypes through median-joining network analysis. Finally, we compared IL37 sequences between the modern and archaic humans. Our results for the first time provide solid evidence that common IL37 variants other than NCBI reference sequence are present worldwide. Our data also supports that IL37 variants are shaped and maintained by selection instead of neutral evolution. We further identified that human IL37 variants consist of two major haplogroups and their presence in archaic humans corroborates its ancient origin in hominid evolution. In conclusion, these data indicate that common IL37 variants are maintained among human populations by selective force, suggesting their potential involvements in immune regulation and human diseases. In addition, the ancient history of IL37 variants reveals interesting insight into the complicated human evolutionary history.

Syntheses, structures, and optical properties of Ba4Ga4SnSe12 and Ba6Ga2SnSe11

Two new quaternary selenides Ba₄Ga₄SnSe₁₂ and Ba₆Ga₂SnSe₁₁, representing the first two members in the A/M/Sn/Q (A = alkaline-earth metal; M = Al, Ga, In; Q = S, Se, Te) system, have been synthesized.

Identification of differentially-expressed genes in intestinal gastric cancer by microarray analysis

Gastric cancer (GC) is one of the most frequent malignant tumors. In order to systematically characterize the cellular and molecular mechanisms of intestinal GC development, in this study, we used 22K oligonucleotide microarrays and bioinformatics analysis to evaluate the gene expression profiles of GC in 45 tissue samples, including 20 intestinal GC tissue samples, 20 normal appearing tissues (NATs) adjacent to tumors and 5 noncancerous gastric mucosa tissue samples. These profiles allowed us to explore the transcriptional characteristics of GC and determine the change patterns in gene expression that may be of clinical significance. 1519 and 1255 differentially-expressed genes (DEGs) were identified in intestinal GC tissues and NATs, respectively, as determined by Bayesian analysis (P<0.001). These genes were associated with diverse functions such as mucosa secretion, metabolism, proliferation, signaling and development, which occur at different stages of GC development.

Effects of dietary cholesterol supplementation on growth and cholesterol metabolism of rainbow trout (Oncorhynchus mykiss) fed diets with cottonseed meal or rapeseed meal

This study was conducted to evaluate the effects of cholesterol on growth and cholesterol metabolism of rainbow trout (Oncorhynchus mykiss) fed diets with cottonseed meal (CSM) or rapeseed meal (RSM). Four experimental diets were formulated to contain 550 g kg(-1) CSM or 450 g kg(-1) RSM with or without 9 g kg(-1) supplemental cholesterol. Growth rate and feed utilization efficiency of fish fed diets with 450 g kg(-1) RSM were inferior to fish fed diets with 550 g kg(-1) CSM regardless of cholesterol level. Dietary cholesterol supplementation increased the growth rate of fish fed diets with RSM, and growth rate and feed utilization efficiency of fish fed diets with CSM. Similarly, dietary cholesterol supplementation increased the plasma total cholesterol (TC), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triiodothyronine levels, but decreased the plasma triglycerides and cortisol levels of fish fed diets with RSM or CSM. In addition, supplemental cholesterol increased the free cholesterol and TC levels in intestinal contents, but decreased the hepatic 3-hydroxy-3-methyl-glutaryl-CoA reductase activity of fish fed diets with RSM or CSM. These results indicate that 9 g kg(-1) cholesterol supplementation seems to improve the growth of rainbow trout fed diets with CSM or RSM, and the growth-promoting action may be related to the alleviation of the negative effects caused by antinutritional factors and/or make up for the deficiency of endogenous cholesterol in rainbow trout.

Biological Targeting of Plasmonic Nanoparticles Improves Cellular Imaging via the Enhanced Scattering in the Aggregates Formed

Gold nanoparticles (AuNPs) demonstrate great promise in biomedical applications due to their plasmonically enhanced imaging properties. When in close proximity, AuNPs plasmonic fields couple together, increasing their scattering cross-section due to the formation of hot spots, improving their imaging utility. In the present study, we modified the AuNPs surface with different peptides to target the nucleus and/or the cell as a whole, resulting in similar cellular uptake but different scattering intensities. Nuclear-targeted AuNPs showed the greatest scattering due to the formation of denser nanoparticle clusters (i.e., increased localization). We also obtained a dynamic profile of AuNP localization in living cells, indicating that nuclear localization is directly related to the number of nuclear-targeting peptides on the AuNP surface. Increased localization led to increased plasmonic field coupling, resulting in significantly higher scattering intensity. Thus, biochemical targeting of plasmonic nanoparticles to subcellular components is expected to lead to more resolved imaging of cellular processes.

[Association of C677T gene polymorphisms of methylenetetrahydrofolate reductase and plasma homocysteine level with hyperlipidemia]

OBJECTIVE

To study the association of methylenetetrahydrofolate reductase (MTHFR) gene C677T mutation and plasma homocysteine (Hcy) levels with hyperlipidemia.

METHODS

Blood samples were collected from 1591 adults for detecting MTHFR gene C677T polymorphism with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), plasma Hcy levels with enzymatic cycling method, and blood lipid levels as well. The patients were divided according to the lipid levels into hyperlipidemia group (n=694) and healthy control group (n=897) and the differences in MTHFR gene C677T polymorphisms and plasma Hcy levels were compared.

RESULTS

The hyperlipidemia group and healthy control group showed no significant differences in CC, CT, or TT genotype frequencies or C and T allele frequencies of MTHFR C677T gene, and had comparable plasma Hcy levels (P>0.05). Patients with 3 different MTHFR C677T genotypes had significant differences in plasma Hcy levels (P<0.01) but not in blood lipid levels (P>0.05). Pairwise comparison indicated a significantly higher plasma Hcy level in TT genotype than in CC and CT genotypes (P<0.01), and the latter two genotypes showed no significant difference (P>0.05).

CONCLUSION

MTHFR C677T polymorphisms and plasma Hcy levels are closely related but neither of them is associated with hyperlipidemia. The TT genotype is associated with a significantly higher plasma Hcy level than CC and CT genotypes.

Observing real-time molecular event dynamics of apoptosis in living cancer cells using nuclear-targeted plasmonically enhanced Raman nanoprobes

Apoptosis is a biological process that plays important roles in embryogenesis, aging, and various diseases. During the process of apoptosis, cells undergo a series of morphological and molecular events such as blebbing, cell shrinkage, proteolysis, and nuclear DNA fragmentation. Investigating these events on a molecular level is crucial for gaining a more complete understanding of the intricate mechanism of apoptosis; however, the simultaneous direct observation of morphological and molecular events in real-time on a single living cell scale still remains a challenge. Herein, we directly monitored morphological and molecular events during cellular apoptosis in real-time after the treatment of an apoptosis-inducing agent, by utilizing our previously described plasmonically enhanced Rayleigh/Raman spectroscopic technique. Spectroscopic analysis of the DNA/protein composition around the cell nucleus revealed the occurrence and dynamics of three apoptotic molecular events: protein denaturation, proteolysis, and DNA fragmentation. The molecular event dynamics were used to create a temporal profile of apoptotic events in single cells. It is found that the sequence of events occurring in the apoptotic process induced by hydrogen peroxide addition is protein denaturation through disulfide bond breakage as well as DNA fragmentation, followed in time by protein unraveling with hydrophobic amino acid exposure, and finally protein degradation. These results demonstrate the potential of using this time-dependent plasmonically enhanced vibrational imaging technique to study the detailed mechanism of other apoptosis molecular pathways induced by different agents (e.g., anticancer drugs). A note is given in the conclusion discussing the expected large difference between the SERS spectrum of biological molecules in solution and that observed in live cells which are enhanced by the plasmonic field of the aggregated nanoparticles.

Resolution of intussusception after spontaneous expulsion of an ileal lipoma per rectum: a case report and literature review

We herein report a case of spontaneous rectal expulsion of an ileal lipoma in a 65-year-old female patient who presented with recurrent attacks of subacute intestinal obstruction. During each episode, the patient developed severe abdominal pain and expelled a fleshy mass from her rectum. The fleshy mass was histopathologically diagnosed as a lipoma comprising fat cells, fibers, and blood vessels. Upon expulsion, the pain disappeared and the intussusception was immediately resolved. Colonoscopic examination revealed a 2.5-cm diameter ulcerated lesion near the ileocecal valve, which was confirmed to be inflammation by pathological examination. A subsequent barium series revealed a normal colonic tract, and the patient remained completely symptom-free for 4 months after the incident. According to the relevant literature and our clinical experience, the treatment method for a lipoma depends on the patient’s clinical manifestations and the size of the tumor. However, the various diagnostic and therapeutic modalities currently available continue to be debated; whether an asymptomatic lipoma requires treatment is controversial. When histopathological examination results allow for the exclusion of malignant lesions such as sarcoma, a lipoma can be resected surgically.

Influences of IL-6R antibody on PMMA bone cement-mediated expression of OPG and RANKL in synovial fibroblasts

Effect of interleukin-6 receptor (IL-6R) antibody on polymethyl methacrylate (PMMA) bone cement-mediated expression of osteoprotegerin (OPG) and receptor activator of nuclear factor-kappaB ligand (RANKL) in synovial fibroblasts was investigated. Synovial tissue obtained from total knee arthroplasty was digested and cultured. Inverted microscope was employed to observe the synovial cells and immunocytochemistry (SABC method) staining was used to identify synovial fibroblasts. This experiment was divided into three groups according to different culture media: PMMA group (75 μg/mL PMMA bone cement particles), IL-6R antibody group (10 ng/mL IL-6R antibody+75 μg/mL PMMA bone cement particles), and control group (no IL-6R antibody or PMMA bone cement particles). Influence of IL-6R antibody and PMMA on proliferation of synovial fibroblasts was measured by cell counting kit-8 (CCK-8). ELISA method was used to measure OPG and RANKL levels in culture solution. Fluorescence quantitative real-time PCR (FQ-PCR) was used to detect the expression of OPG and RANKL mRNA. After three consecutive passages, more than 95% of the primary synovial cells became long spindle fibroblast-like cells. SABC staining results showed that the fibroblast-like cells were negative for anti-CD68 antibody and positive for anti-vimentin antibody, with brown madder stained. CCK-8 test demonstrated that the absorbance (A) value at 450 nm was significantly lower in IL-6R antibody group than in PMMA group and control group (P<0.01), but there was no statistically significant difference in A value at 450 nm between the control group and PMMA group (P>0.05). Results of ELISA indicated that the expression of OPG was significantly higher in IL-6R antibody group than in PMMA group and control group (P<0.01). The expression of RANKL was inhibited (P<0.05), and the ratio of OPG/RANKL was significantly increased in IL-6R antibody group as compared with PMMA group and control group. There was no significant difference in the expression of OPG between control group and PMMA group (P>0.05), but the expression of RANKL was higher in PMMA group than in control group (P<0.05), and there was a significant difference in the ratio of OPG/RANKL between them (P<0.05). Results of FQ-PCR revealed the expression of RANKL mRNA was significantly inhibited (P<0.01) and the expression of OPG mRNA was significantly increased (P<0.01) in IL-6R antibody group as compared with PMMA group and control group. The expression of RANKL mRNA was higher in PMMA group than in control group (P<0.05), but the expression of OPG mRNA had no significant difference between them (P>0.05). IL-6R antibody could significantly increase the expression of OPG, but inhibit the expression of RANKL, which might provide a theoretical basis of molecular biology for the prevention and treatment of aseptic loosening of prosthesis.

Regulation of cancer stem cells by RING finger ubiquitin ligases

Like normal stem cells, cancer stem cells (CSCs) are capable of self-renewal, either by symmetric or asymmetric cell division. They have the exclusive ability to reproduce malignant tumors indefinitely, and to confer resistance in response to radiation or chemotherapy. The ubiquitin modification system plays various roles in physiology and pathology. The key component for the specificity of this system is ubiquitin ligases (E3s). Of these E3s, the majority are RING finger proteins. Many RING finger E3s, such as the Cullin1-Skp1-F-box protein (SCF) E3s, CBL, BRCA1, MDM2 and von Hippel-Lindau tumour suppressor (VHL), are crucial in the regulation of cell-cycle progression and cell differentiation. As a result, many RING finger E3s are implicated in the positive and negative regulation of CSC maintenance. This review summarizes current knowledge in this research field.

[Effect of water velocity on swimming behavior of juvenile Megalobrama amblycephala]

To investigate the swimming behavior of juvenile Megalobrama amblycephala, a tracking analysis device was designed to monitor behavior indicators including velocity (V), swimming distance (SD), turn angle (TA), distance to center-point (DC) and swimming track (ST) at different flow rates (0, 0.1, 0.2, 0.3 and 0.4 m/s) at 25℃. Results showed that indicator values all increased with increasing flow rate. Values of V, SD and TA showed no significant differences among the flow rates of 0, 0.1 and 0.2 m/s, respectively (P>0.05). However, they increased obviously at flow rates of 0.3 and 0.4 m/s (P<0.05), with no significant differences found between these two flow rates (P>0.05). The SD value did not change markedly according to flow rates (P>0.05), while ST showed complex patterns corresponding to increasing flow rate. A significant linear positive correlation occurred in free-swimming fish between V and SD, while a negative relationship was found between V and TA. No regular relationship was deduced between swimming speed and DC.

Id proteins: small molecules, mighty regulators

The family of inhibitor of differentiation (Id) proteins is a group of evolutionarily conserved molecules, which play important regulatory roles in organisms ranging from Drosophila to humans. Id proteins are small polypeptides harboring a helix-loop-helix (HLH) motif, which are best known to mediate dimerization with other basic HLH proteins, primarily E proteins. Because Id proteins do not possess the basic amino acids adjacent to the HLH motif necessary for DNA binding, Id proteins inhibit the function of E protein homodimers, as well as heterodimers between E proteins and tissue-specific bHLH proteins. However, Id proteins have also been shown to have E protein-independent functions. The Id genes are broadly but differentially expressed in a variety of cell types. Transcription of the Id genes is controlled by transcription factors such as C/EBPβ and Egr as well as by signaling pathways triggered by different stimuli, which include bone morphogenic proteins, cytokines, and ligands of T cell receptors. In general, Id proteins are capable of inhibiting the differentiation of progenitors of different cell types, promoting cell-cycle progression, delaying cellular senescence, and facilitating cell migration. These properties of Id proteins enable them to play significant roles in stem cell maintenance, vasculogenesis, tumorigenesis and metastasis, the development of the immune system, and energy metabolism. In this review, we intend to highlight the current understanding of the function of Id proteins and discuss gaps in our knowledge about the mechanisms whereby Id proteins exert their diverse effects in multiple cellular processes.

Mitochondrial genome of Monotrete leiurus (Osteichthyes: Tetraodontidae)

Monotrete leiurus is the only freshwater puffer founded in Nala River, which is a tributary of the Langcang-Mekong River in China. The complete mitochondrial genome sequence of the Monotrete leiurus is 16,448 bp long and consists of 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and 1 control region (CR). The base composition of the genome is 29% A, 23.8% T, 31.8% C and 15.4% G and this composition shows a bias for A + T. The mitochondrial genes from Monotrete leiurus are overlapped in a total of 34 bp at seven locations and interleaved with a total of 64 bp intergenic spacers at 13 locations. The results can not only help clarify the classification problem in sibling freshwater puffers, but also provide information for their protection in the future.

What do the occurrences of migratory fishes in the Upper Mekong mean?

This paper examines the recent appearance of four migratory species in the Upper Mekong: Dasyatis laosensis, Anguilla bicolor, Anguilla marmorata, and Chitala ornata. Since 2006 these species have been continually sampled in an area below Jinghong Dam in Xishuangbanna, China. This region is far beyond their historical upstream distribution, and the reasons for these appearances and their subsequent impact on river ecosystem are considered.