The study of isotopic enrichment of water in human plasma and erythrocyte.

Life does not sustain without water. For water, there is a natural abundance of stable isotope hydrogen and oxygen. Water molecules get across cell membranes through a plasma membrane protein, named aquaporin. Moreover, the kidney is the main organ to maintain water homeostasis. Here, we study the stable isotopic ratios of hydrogen and oxygen in human blood plasma and erythrocyte corresponding to kidney functions. We extract waters from human plasma and erythrocyte, collected from 110 participants, including 51 clinically stable outpatients with end-stage renal disease (ESRD) and 59 subjects with normal renal function (NRF). We observed that (i) both extracellular (blood plasma) and intracellular (erythrocyte) biology waters are isotopic differences between the ESRD and NRF participants, (ii) the natural abundance of isotopic waters of ESRD is hypo-isotopic, and (iii) the isotopic enrichment of water between erythrocyte and blood plasma are distinct. In addition, we introduce an empirical formula using entropy transformation to describe isotopic water enrichment for biology. Accordingly, the natural abundance of stable isotope water of blood plasma and erythrocyte may be possibly put in practice a new sign for assessments of kidney dysfunctions.

Investigation of the variants at the binding site of inflammatory transcription factor NF-κB in patients with end-stage renal disease.

BACKGROUND: A chronic inflammatory state is a prominent feature in patients with end-stage renal disease (ESRD). Nuclear factor-kappa B (NF-κB) is a transcription factor that regulates the expression of genes involved in inflammation. Some genetic studies have demonstrated that the NF-κB genetic mutation could cause kidney injury and kidney disease progression. However, the association of a gene polymorphism in the transcription factor binding site of NF-κB with kidney disease is not clear. METHODS: We used the Taiwan Biobank database, the University of California, Santa Cruz, reference genome, and a chromatin immunoprecipitation sequencing database to find single nucleotide polymorphisms (SNPs) at potential binding sites of NF-κB. In addition, we performed a case-control study and genotyped 847 patients with ESRD and 846 healthy controls at Tri-Service General Hospital from 2015 to 2016. Furthermore, we used the ChIP assay to identify the binding activity of different genotypes and used Luciferase reporter assay to examine the function of the rs9395890 polymorphism. RESULT: The results of biometric screening in the databases revealed 15 SNPs with the potential binding site of NF-κB. Genotype distributions of rs9395890 were significantly different in ESRD cases and healthy controls (P = 0.049). The ChIP assay revealed an approximately 1.49-fold enrichment of NF-κB of the variant type TT when compared to that of the wild-type GG in rs9395890 (P = 0.027; TT = 3.20 ± 0.16, GT = 2.81 ± 0.20, GG = 1.71 ± 0.18). The luciferase reporter assay showed that the NF-κB binding site activity in T allele was slightly higher than that in G allele, though it is not significant. CONCLUSIONS: Our findings indicate that rs9395890 is associated with susceptibility to ESRD in Taiwan population.

Assessment of renal function by the stable oxygen and hydrogen isotopes in human blood plasma.

Water (H(2)O) is the most abundant and important molecule of life. Natural water contains small amount of heavy isotopes. Previously, few animal model studies have shown that the isotopic composition of body water could play important roles in physiology and pathophysiology. Here we study the stable isotopic ratios of hydrogen (δ(2)H) and oxygen (δ(18)O) in human blood plasma. The stable isotopic ratio is defined and determined by δ(sample) = [(R(sample)/R(STD))-1] * 1000, where R is the molar ratio of rare to abundant, for example, (18)O/(16)O. We observe that the δ(2)H and the δ(18)O in human blood plasma are associated with the human renal functions. The water isotope ratios of the δ(2)H and δ(18)O in human blood plasma of the control subjects are comparable to those of the diabetes subjects (with healthy kidney), but are statistically higher than those of the end stage renal disease subjects (p<0.001 for both ANOVA and Student's t-test). In addition, our data indicate the existence of the biological homeostasis of water isotopes in all subjects, except the end stage renal disease subjects under the haemodialysis treatment. Furthermore, the unexpected water contents (δ(2)H and δ(18)O) in blood plasma of body water may shed light on a novel assessment of renal functions.