Association between the c.1564A>T genetic polymorphism of the MDR1 gene and hepatocellular carcinoma in Chinese population

The objective of this study was to evaluate the influence of c.1564A>T genetic polymorphisms in the multidrug resistance 1 gene (MDR1) on hepatocellular carcinoma (HCC) susceptibility through association analysis. A total of 632 HCC patients and 645 cancer-free controls were enrolled in this study. The c.1564A>T genetic polymorphisms were genotyped by created restriction site-polymerase chain reaction (CRS-PCR) and confirmed using DNA sequencing methods. The potential associations of c.1564A>T genetic polymorphisms with the risk of HCC were analyzed by different genetic models. Statistically significantly increased risks of HCC were detected in the homozygote comparison (TT versus AA: OR = 1.70, 95%CI = 1.17-2.45, χ(2) = 7.99, P = 0.005), recessive model (TT versus

AT/AA

OR = 1.64, 95%CI = 1.15-2.33, χ(2) = 7.66, P = 0.006), and allele contrast (T versus A: OR = 1.23, 95%CI = 1.04-1.45, χ(2) = 6.09, P = 0.014). Our data suggest that the genotypes/alleles from c.1564A>T genetic polymorphisms are statistically associated with HCC risk. The allele-T and genotype TT may contribute to susceptibility to HCC in the Chinese Han population.

Histological changes within dental pulps in teeth with moderate-to-severe chronic periodontitis

AIM

To investigate the effect of chronic periodontitis on dental pulps by assessing histological changes in the pulps of teeth with moderate-to-severe periodontitis.

METHODOLOGY

A total of 242 teeth from 162 patients with moderate-to-severe periodontitis were collected, and histological changes in pulps were investigated by staining with haematoxylin and eosin. Baseline data were taken from the patients' records before extraction. The morphologic changes observed in the pulp were classified as degree I, degree II, degree III and degree IV. Statistical analysis of the severity of periodontitis and histological changes with the pulps was applied using the Mann-Whitney U rank sum test, whilst the contingency coefficient was used to analyse the inter-relationship between the severity of periodontitis and histological changes in the pulps.

RESULTS

The inter-relationship between the severity of periodontitis and histological changes in the pulps was 0.274 (P < 0.001), and significant differences existed between teeth with moderate periodontitis and severe periodontitis group (Z = 4.145, P < 0.001). The inter-relationship between attachment loss and histological changes in the pulps was 0.397 (P < 0.001). There were significant differences in the histological changes amongst teeth with various degrees of attachment loss (χ(2) = 33.023, P < 0.001) and amongst teeth in different locations (χ(2) = 23.163, P < 0.001).

CONCLUSIONS

There was a positive association between the severity of periodontitis and histological changes within the pulp. More attachment loss was correlated with pathological changes within the dental pulp.

Self-reported head injury and risk of late-life impairment and AD pathology in an AD center cohort

AIMS

To evaluate the relationship between self-reported head injury and cognitive impairment, dementia, mortality, and Alzheimer's disease (AD)-type pathological changes.

METHODS

Clinical and neuropathological data from participants enrolled in a longitudinal study of aging and cognition (n = 649) were analyzed to assess the chronic effects of self-reported head injury.

RESULTS

The effect of self-reported head injury on the clinical state depended on the age at assessment: for a 1-year increase in age, the OR for the transition to clinical mild cognitive impairment (MCI) at the next visit for participants with a history of head injury was 1.21 and 1.34 for the transition from MCI to dementia. Without respect to age, head injury increased the odds of mortality (OR = 1.54). Moreover, it increased the odds of a pathological diagnosis of AD for men (OR = 1.47) but not women (OR = 1.18). Men with a head injury had higher mean amyloid plaque counts in the neocortex and entorhinal cortex than men without.

CONCLUSIONS

Self-reported head injury is associated with earlier onset, increased risk of cognitive impairment and dementia, increased risk of mortality, and AD-type pathological changes.

Molecular cloning and functional analysis of MRLC2 in Tianfu, Boer, and Chengdu Ma goats

To determine the molecular basis of heterosis in goats, fluorescence quantitative polymerase chain reaction (PCR) was performed to investigate myosin-regulatory light chain 2 (MRLC2) gene expression in the longissimus dorsi muscle tissues of the Tianfu goat and its parents, the Boer and Chengdu Ma goats. The goat MRLC2 gene was differentially expressed in the crossbreed, and the purebred mRNA were isolated and identified using fluorescence quantitative reverse transcription-PCR (RT-PCR). The complete coding sequence of MRLC2 was obtained using the cDNA method, and the full-length coding sequence consisted of 513 bp encoding 172 amino acids. The EF-hand superfamily domain of the MRLC2 protein is well conserved in caprine and other animals. The deduced amino acid sequence of MRLC2 shared significant identity with MRLC2 from other mammals. Phylogenetic tree analysis revealed that the MRLC2 protein was closely related to MRLC2 in other mammals. Several predicted miRNA target sites were found in the coding sequence of caprine MRLC2 mRNA. Analysis by RT-PCR showed that MRLC2 mRNA was present in the heart, stomach, liver, spleen, lung, small intestine, kidney, leg muscle, abdominal muscle, and longissimus dorsi muscles. In particular, the high expression of MRLC2 mRNA was detected in the longissimus dorsi, leg muscle, abdominal muscle, stomach, and heart, but low levels of expression were also observed in the liver, spleen, lung, small intestine, and kidney. The expression of the MRLC2 gene was upregulated in the longissimus dorsi muscle of Boer and Tianfu goats, and it was moderately upregulated in Chengdu Ma goats.

Low-Dose Azithromycin Attenuates OVA-Induced Airway Remodeling and Inflammation via Down-Regulating TGF-βl Expression in RAT

Asthma is characteristic with chronic airway inflammation and remodeling. Azithromycin (AZM), the 15-member macrolide, is known to present an anti-inflammatory effect and is increasingly being used in the treatment of chronic inflammatory pulmonary diseases. We hypothesize that low-dose azithromycin can inhibit allergen-induced airway remodeling except allergic airway inflammation in rat model. Male SD rats underwent intraperitoneal ovalbumin sensitization on days 1 and 6 followed by an intranasal challenge on day 7–13. On day 14, airway inflammation and remodeling were assessed by quantifying leukocytes in the airway, expression of multiple inflammatory mediators in BALF, histological examination in lung and TGF-β1 mRNA and protein levels by qRT-PCR, immunohistochemistry and Western blotting. Treatment with low-dose azithromycin at the dose of 25 mg/kg significantly reduced ovalbumin-dependent airway inflammation, including accumulation of neutrophils, lymphocytes and eosinophils, secretion of IL-2, IL-4, IL-13 and TNF-α. Moreover, airway remodeling was significantly abrogated by azithromycin in this model. The mucus cell hyperplasia, thickening of the peribronchial smooth muscle layer, secretion of ET-1, IL-2, IL-4, IL-13 and TNF-α, and increasing mRNA and protein expressions of TGF-β1 in lung tissue were all significantly decreased in azithromycin-treated rats. These findings demonstrate the protective effect of low-dose azithromycin on allergic airway remodeling in rat and suggest low-dose azithromycin may have beneficial effects in treating allergic airway inflammation.

A new fluorescent staining method for callose of microspore mother cells during meiosis

To observe the dynamic behavior of callose of microspore mother cells during meiosis, we developed a convenient, rapid and efficient staining method using an improved carbol fuchsin/aniline blue solution. The stained microspore mother cells during meiosis showed yellowish green callose, red cytoplasm and dark red chromosomes when excited with blue light, which produced a contrasting image with a three-dimensional effect. When stained with only improved carbol fuchsin solution, the cells had red cytoplasm and chromosomes when excited with green light. The improved carbol fuchsin solution can be used to replace other more expensive DNA-specific dyes, such as DAPI and H33258, to reduce experimental costs.

Two novel DAX1 gene mutations in Chinese patients with X-linked adrenal hypoplasia congenita: clinical, hormonal and genetic analysis

Mutations in the DAX1 gene result in X-linked congenital adrenal hypoplasia (AHC). Affected boys usually present with primary adrenal failure in early infancy or childhood and hypogonadotropic hypogonadism (HH) at puberty. This paper describes the clinical, hormonal, radiological, and genetic characteristics of 2 Chinese patients with X-linked AHC. Primary adrenal insufficiency occurred in the 2 patients during their childhood and HH was recognized at puberty. Genomic DNA was extracted from their peripheral blood leukocytes and coding sequence abnormalities of the DAX1 gene were assessed by PCR and direct sequencing analysis. Genetic analysis of the DAX1 gene revealed 2 novel mutations c.572-575 dupGGGC, p.Thr193Gly,fs,205X and c.773- 774 dupCC, p.Ser259Pro,fs,264X in exon 1, causing frameshifts and yeilding premature stop codons at 205 and 264, respectively. This study identifies 2 novel mutations in the DAX1 gene which can further expand the mutation database and benefit patients in the diagnosis and treatment of AHC.

Autophagy is involved in traumatic brain injury-induced cell death and contributes to functional outcome deficits in mice

Previous data demonstrate that traumatic brain injury (TBI) activates autophagy, and increases microtubule-associated protein 1 light chain 3 (LC3) immunostaining mainly in neurons. However, the role of autophagy in traumatic brain damage remains elusive. The aim of the present study was to investigate the autophagic mechanisms participating in traumatic brain injury. The autophagy inhibitors 3-methyladenine (3-MA) and bafliomycin A1 (BFA) were administered with a single i.c.v. injection before TBI. We first examined the protein levels of Beclin-1 and LC3 II, which have been found to promote autophagy previously. Immunoblotting analysis showed that 3-MA pretreatment reduced post-TBI Beclin-1 and LC3-II levels, and maintained p62/SQSTM1 (p62) levels. In addition, double immunolabeling showed that the increased punctate LC3-II dots colocalizing with Propidium Iodide (PI)-stained nuclei at 24 h after injury, were partially inhibited by 3-MA pretreatment. Furthermore, inhibition of autophagy could reduce TBI-induced cell injury assessed with i.p. injection of PI and lesion volume, and attenuate behavioral outcome evaluated by motor test and Morris water maze. The neuroprotective effects were associated with an inhibition on TBI-induced up-regulation of LC3, Beclin-1, cathepsin B, caspase-3 and the Beclin-1/Bcl-2 ratio. Taken together, these data imply that the autophagy pathway is involved in the pathophysiologic responses after TBI, and inhibition of this pathway may help attenuate traumatic damage and functional outcome deficits.

Genetic polymorphisms of the DNA repair gene MPG may be associated with susceptibility to rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease and can lead to deformities and severe disabilities, due to irreversible damage of tendons, joints, and bones. A previous study indicated that a DNA repair system was involved in the development of RA. In this study, we investigated the association of four N-methylpurine-DNA glycosylase (MPG) gene polymorphisms (rs3176364, rs710079, rs2858056, and rs2541632) with susceptibility to RA in 384 Taiwanese individuals (192 RA patients and 192 control subjects). Our data show a statistically significant difference in genotype frequency distributions at rs710079 and rs2858056 SNPs between RA patients and control groups (P = 0.040 and 0.029, respectively). Our data also indicated that individuals with the GG genotype at rs2858056 SNP may have a higher risk of developing RA. In addition, compared with the haplotype frequencies between case and control groups, individuals with the GCGC haplotype appeared to be at a greater risk of RA progression (P = 0.003, OR = 1.75; 95&percnt; CI = 1.20-1.55). Our results suggest that rs710079 and rs2858056 polymorphisms and the GCGC haplotype in the MPG gene are associated with the risk of RA progression, and thus may be used as molecular markers of RA if they are confirmed by further research.

Association of TNF-alpha gene polymorphisms with systemic lupus erythematosus in Taiwanese patients

Tumour necrosis factor-alpha (TNF-alpha), an important proinflammatory cytokine, exerts a variety of physiological and pathogenic effects that lead to tissue destruction. Studies on the association of TNF-alpha genetic polymorphisms with systemic lupus erythematosus (SLE) have yielded inconclusive results. We investigated the association of TNF-alpha genetic polymorphisms (-1031T/C, -863C/A, -857T/C, -308A/G and +489A/G) with SLE in Taiwanese patients and controls. Our results indicate that 1) the frequency of the A-allele at -863 position was significantly higher in SLE patients (odds ratio = 1.46; 95% CI = 1.02-2.08); 2) the frequency of the A-allele at +489 position was significantly higher in SLE patients (odds ratio = 1.79; 95% CI = 1.21-2.65); 3) the AA or GA genotype frequencies at +489 position were significantly increased in SLE patients (AA genotype: odds ratio = 11.20; 95% CI = 1.36-92.55; GA genotype: odds ratio = 1.63; 95% CI = 1.03-2.58); 4) no significant association of TNF-alpha haplotypic distributions was observed, except for the haplotypes TCCGA, CACGA and CCCGG; and 5) the genotype frequency of the polymorphisms at -1031 was significantly different in patients with antinuclear antibodies (P = 0.022). The allele and genotype frequencies of the polymorphisms at -863 were not significantly different. The genotype frequency of the polymorphisms at -857 was significantly different in patients with haematological disorder (P = 0.025). The frequency of A allele of the polymorphisms at -308 was significantly increased in patients with malar rash (P = 0.033), discoid rash (P = 0.023), photosensitivity (P = 0.037), oral ulcers (P = 0.002) and serositis (P = 0.029). The genotype frequency of the polymorphisms at +489 was significantly different in patients with discoid rash and photosensitivity (data not shown; discoid rash, P = 0.031; photosensitivity, P = 0.044). These results suggest that TNF-alpha genetic polymorphisms contribute to SLE susceptibility in the Taiwanese population.

Polymorphisms in the DNA repair gene XRCC1 and associations with systemic lupus erythematosus risk in the Taiwanese Han Chinese population

XRCC1 plays a central role in mammalian DNA repair processes. Two polymorphisms of XRCC1, rs1799782 (Arg > Trp at codon 194) and rs25487 (Arg > Gln at codon 399), are common in the Han Chinese population. Our objective was to analyze the relationship between these two functional single-nucleotide polymorphisms (SNPs) and systemic lupus erythematosus (SLE) in the Taiwanese Han Chinese population. Genotyping was performed by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) on 172 SLE patients and 160 normal controls. Our data indicate that the frequency of A/G at codon 399 differed between patients and controls (p = 0.01; odds ratio: 1.80; 95% confidence interval: 1.17-2.75), but the allelic frequency analysis did not reveal significant differences. For the SNP at codon 194, there were no differences in either allelic or genotype frequencies between SLE patients and normal subjects. Clinical association studies of SLE symptoms revealed the involvement of the A/G polymorphism at codon 399 in SLE pathogenesis. Our results indicate that a functional SNP at codon 399 of XRCC1 is associated with the development of SLE.