Hsin Ping Liu

Evaluation of the poly(ADP-ribose) polymerase-1 gene variants in Alzheimer's disease

Amyloid peptide is thought to play a critical role in neuronal death in Alzheimers disease (AD), most likely through oxidative stress. Free radical‐related injury leads to DNA breaks, which subsequently activates the repair enzyme poly(ADP‐ribose) polymerase‐1 (PARP‐1). In this study, the relationship between genetic variants situated at the PARP‐1 gene and AD development was investigated. We performed a case and control study from a Taiwanese population enrolled 120 AD patients and 111 healthy controls by using a polymerase chain reaction restriction fragment length polymorphism approach for two PARP‐1 exonic polymorphisms, 414C/T (rs1805404) and 2456T/C (rs1136410), corresponding to protein residues at positions 81Asp/Asp and762Val/Ala. There were no significant differences in allele or genotype frequencies for either PARP‐1 gene variant between the case and control groups; however, upon analysis of the haplotype distribution, four haplotypes (Hts) were identified. We found that the distributions of Ht3‐TT and Ht4‐CC were significantly associated with an increased risk of AD (P<0.0001), whereas the Ht1‐TC haplotype showed a protective effect for cases compared with the control group (P<0.05). These results reveal that the PARP‐1 gene is highly associated with AD susceptibility and might contribute to a critical mechanism that mediates cell survival or death as a response to cytotoxic stress. J. Clin. Lab. Anal. 24:182–186, 2010.

Ethylene glycol induces calcium oxalate crystal deposition in Malpighian tubules: a Drosophila model for nephrolithiasis/urolithiasis

Several animal species are used to study calcium oxalate urolithiasis; however, an ideal model has yet to be identified. We used Drosophila as a model organism and fed the flies lithogenic agents such as ethylene glycol, hydroxyl-L-proline, and sodium oxalate. At different times, the Malpighian tubules, the kidney equivalent of insects, were dissected and a polarized light microscope used to highlight the birefringent crystals. Scanning electron microscopy and energy-dispersive X-ray spectroscopy confirmed that the crystal composition was predominately calcium oxalate. Furthermore, administration of potassium citrate successfully reduced the quantity of and modulated the integrity of the ethylene glycol-induced crystals. Thus, the Drosophila model of bio-mineralization produces crystals in the urinary system through many lithogenic agents, permits observation of crystal formation, and is amenable to genetic manipulation. This model may mimic the etiology and clinical manifestations of calcium oxalate stone formation and aid in identification of the genetic basis of this disease.

Identification of melamine/cyanuric acid-containing nephrolithiasis by infrared spectroscopy.

Melamine‐contaminated milk formula caused infant nephrolithiasis in some areas of China. Its combination with cyanuric acid causes crystallization in renal tubules. Following this renal damage and even renal failure that require long‐term hemodialysis has been reported. Therefore, correct and timely diagnosis of these complex diseases is critical. Melamine containing stone is a combination of equal molar ratios of common stone compositions that has been reported from previous animal studies. We have previously identified the compositions of urinary tract stones with infrared (IR) spectroscopy. We hypothesized that the absorbance of wavelength of IR can identify melamine/cyanuric acid in the presence of mixing human stone compositions. In this study, we made an artificial stone composition and examine under IR absorbance by mixing equal molar ratios of melamine/cyanuric acid with different types of human urinary stones, and established a reference of IR analysis for the identification of melamine/cyanuric acid‐containing human urinary tract stones. Knowledge of the precise stone composition allowed institution of appropriate prophylactic dietary and medical therapy and this may help in the prevention of urinary stone recurrence. The results are promising that melamine and cyanuric acid can be identified clearly in a low percentile (∼1%) of stone mixture pellet. Therefore, IR seems to be an ideal tool for the identification of melamine/cyanuric acid‐containing stones. J. Clin. Lab. Anal. 24:92–99, 2010.

A novel genetic variant of BMP2K contributes to high myopia.

Loss of eye growth regulation may cause myopia, because modulation of optic globe size is essential for the generation of normal optic power. Evidence has implied variations of BMP2 gene expression mediate ocular development and retinal tissue remodeling. Given BMP2 as a potential regulator involved in myopia development, we investigate whether gene BMP2‐inducible kinase (BMP2K, BIKe), whose expression is up‐regulated during BMP2‐induced osteoblast differentiation, contributes to susceptibility of high myopia. Participants grouped into high myopia had a spherical equivalent greater than −6.00 D, compared with a control group of spherical equivalent less than −0.5 D. Genotyping of polymorphisms 1379 G/A (rs2288255) and 3171 C/G (rs12507099), corresponding with 405 Gly/Ser and 1002 Thr/Ser variation in the BMP2K gene were determined by PCR‐restriction fragment length polymorphism and associative study performed by comparing high myopic subjects and healthy controls. The frequency of A allele in the BMP2K gene 1379 G/A polymorphism showed a significant difference between cases and controls (P<0.001, OR=2.99, 95% CI=1.62–5.54) and subjects with either AA or AG genotype show higher risk than GG genotype (P<0.001, OR=3.07, 95% CI=1.59–5.92), while 3171 C/G polymorphism was not significant from this survey. These data suggest that BMP2K gene 1379 G/A variant is strongly correlated with high myopia and may contribute to a genetic risk factor for high degrees of myopic pathogenesis. J. Clin. Lab. Anal. 23:362–367, 2009.

Genetic Variation in N-Methyl-D-Aspartate Receptor Subunit NR3A but Not NR3B Influences Susceptibility to Alzheimer’s Disease

Background: The administration of memantine, an N-methyl-D-aspartate (NMDA) receptor antagonist, has clinically improved the cognitive function of patients with Alzheimer’s disease (AD), indicating that a disturbance in glutamatergic transmission might be involved in a predisposition to developing the disease. Aim: The potential association of polymorphisms in NMDA receptor subunits NR3A and NR3B, encoded by the GRIN3A and GRIN3B genes, with AD was investigated. Methods: We performed a case-control study. Two single nucleotide polymorphisms, 3104 G/A (rs10989563) and 3723 G/A (rs3739722), in the GRIN3A gene and 2 GRIN3B gene polymorphisms, 1210 C/T (rs4807399) and 1730 C/T (rs2240158), were studied. Results: Upon genotyping of the exonic polymorphism in the GRIN3A gene, the G allele was present at a higher rate than the A allele at position 3723 in AD patients compared with normal groups (p < 0.05). Three haplotypes (designated Ht1–3) were identified from these 2 polymorphisms (3104 G/A and 3723 G/A), and the distribution of Ht2 (AG) differed between AD patients and controls (p < 0.05). Additionally, from the 2 GRIN3B gene variants 1210 C/T and 1730 C/T analyzed, no strong association with AD was observed. Conclusion: These observations suggest that the genetic variation of the NR3A, but not NR3B, subunit of the NMDA receptor may be a risk factor for AD pathogenesis among the Taiwanese population.

The Yang-Tonifying Herbal Medicine Cynomorium songaricum Extends Lifespan and Delays Aging in Drosophila

Aging is highly correlated with the progressive loss of physiological function, including cognitive behavior and reproductive capacity, as well as an increased susceptibility to diseases; therefore, slowing age-related degeneration could greatly contribute to human health. Cynomorium songaricum Rupr. (CS) is traditionally used to improve sexual function and treat kidney dysfunction in traditional Chinese medicine, although little is known about whether CS has effects on longevity. Here, we show that CS supplementation in the diet extends both the mean and maximum lifespan of adult female flies. The increase in lifespan with CS was correlated with higher resistance to oxidative stress and starvation and lower lipid hydroperoxides (LPO) levels. Additionally, the lifespan extension was accompanied by beneficial effects, such as improved mating readiness, increased fecundity, and suppression of age-related learning impairment in aged flies. These findings demonstrate the important antiaging effects of CS and indicate the potential applicability of dietary intervention with CS to enhance health and prevent multiple age-related diseases.

G/T polymorphism in the interleukin-2 exon 1 region among Han Chinese systemic lupus erythematosus patients in Taiwan

Interleukin-2 (IL-2), one of the crucial immunoregulatory cytokines required for T lymphocyte activation, plays an important role in autoimmune diseases. An IL-2 genetic G/T polymorphism (rs2069763) has been linked with multiple sclerosis and rheumatoid arthritis. We tested a hypothesis that this polymorphism confers systemic lupus erythematosus (SLE) susceptibility. Study participants were Han Chinese SLE patients and a healthy control group in Taiwan. Our results indicate (a) a significantly higher G allele frequency in SLE patients (P=1.91 x 10(-14); OR=3.94; 95% CI=2.74-5.66), (b) a significantly higher G allele frequency in SLE patients with antinuclear antibodies (ANA) (P=0.033; OR=4.21; 95% CI=1.01-17.51) and (c) a significantly lower G allele frequency in SLE patients with discoid rash (P=0.019; OR=0.41; 95% CI=0.19-0.88). Our results suggest that this polymorphism may be involved in the genetic background of Taiwanese SLE.

Association of interleukin-18 gene polymorphisms with calcium oxalate kidney stone disease

Abstract Objective. The interleukin-18 (IL-18) encoding gene has three common single-nucleotide polymorphisms at –607C/A, –137G/C and +105A/C, which have been reported to be associated with several diseases. The aim of this study is to test whether IL-18 polymorphisms could act as genetic markers for renal stone disease. Material and methods. A control group of 104 healthy subjects, and 272 patients with recurrent calcium oxalate stones were examined. Polymerase chain reaction-based restriction endonuclease analysis was used to detect IL-18 polymorphisms. Results. The patient and control groups differed significantly in genotypic expression of the IL-18 +105A/C polymorphism. The prevalence of the A/C + C/C genotypes in the patients was higher than that in the controls. The allelic frequency of IL-18 +105A/C differed significantly between the patients and the controls. The odds ratio (OR) of the A/C heterozygote of IL-18 +105A/C associated with urolithiasis was 2.772. The OR of the A/C + C/C genotypes of IL-18 +105A/C associated with urolithiasis was 3.097. The OR per copy of the C allele of IL-18 +105A/C associated with urolithiasis was 4.143. There were also significant differences in the prevalence of genotype IL-18 –137G/C polymorphisms between the patients and controls. The distribution of the G/G homozygote in the patients was higher than that in the controls. There was no significant difference in genotype and allelic frequency at the IL-18 –607C/A polymorphism between patients and control subjects. Conclusion. The results indicate that IL-18 +105A/C polymorphisms may play a role in the development of urolithiasis.

Matrix metalloproteinase 14 modulates diabetes and Alzheimer’s disease cross-talk: a meta-analysis

Diabetes mellitus is associated with dementia, but whether diabetes is associated with Alzheimer’s disease remains controversial. Alzheimer’s disease is characterized by amyloid beta aggregation. We hypothesized that genes, involved in amyloid beta degradation, may be altered due to diabetes and thus participate in progression of Alzheimer’s disease. Expression profiling of amyloid beta-degrading enzymes in streptozotocin-induced diabetic mice and their correlation with expression of amyloid precursor protein in hippocampus of Alzheimer’s disease patients were accessed. We found that matrix metalloproteinase 14 decreased in brain but not in other tissues of streptozotocin-induced diabetic mice, and was negatively correlated with expression of amyloid precursor protein in hippocampus of Alzheimer’s disease patients. These findings suggested matrix metalloproteinase 14 may link insulin-deficient diabetes to Alzheimer’s disease.

Molecular pathways related to the longevity promotion and cognitive improvement of Cistanche tubulosa in Drosophila

BACKGROUND The aging process, including physical dysfunction and age-related memory impairment (AMI), are considered to be correlated with cumulative oxidative damages and insulin/IGF-1 signaling pathway. PURPOSE The present study was to elucidate the in vivo effects on delaying aging and ameliorating AMI and underlying molecular mechanisms of Cistanche tubulosa (CT), a herb used in traditional Chinese medicine to improve sexual function and treat kidney dysfunction. METHODS The flies, treated and untreated with CT, were observed for lifespan, resistance to oxidative stress with H2O2 or paraquat, starvation assay, cognitive behaviors with T-maze, and transcript levels of target genes with quantitative RT-PCR. RESULTS Administering CT extended the mean and maximum lifespan and increased resistance to oxidative stress in flies. CT supplementation also enhanced memory formation in young flies and suppressed AMI upon aging. Several genes and signaling pathways, including the mechanistic target of rapamycin (mTOR) and Notch networks, have been identified as causing these pharmacological effects and alterations in the gene expression of glutamate receptors. CONCLUSION Our results indicate that CT supplementation may contribute to slowing aging phenotypes and alleviating cognitive behavioral decline in flies, indicating potential applicability for enhancing human health and reducing susceptibility to age-related disorders.