Kinetics of glycogen synthase kinase (GSK)3β and phosphorylated GSK3β (Ser 9) expression in experimentally induced periapical lesions

AIM

To investigate the kinetics of GSK3β and p-GSK3β (Ser 9) expression in experimentally induced rat periapical lesions and to explore their possible functions in the pathogenesis of periapical lesions.

METHODOLOGY

Periapical lesions were established in Wistar rats by occlusal pulp exposure in mandibular first molar teeth. The animals were killed on days 0, 7, 14, 21 and 28. Micro-computed tomographic, histological and enzyme histochemical analyses were performed to detect the progression of periapical lesions. Immunohistochemistry, double-dye immunofluorescence and Western blot were performed to determine the expression of GSK3β and p-GSK3β (Ser 9) in periapical tissues.

RESULTS

From day 0 to day 28, the lesion volume and area gradually expanded, and the GSK3β-positive cells gradually ascended. A few p-GSK3β (Ser 9)-positive cells and osteoclasts appeared on day 7 and then climaxed on day 14. The numbers then simultaneously decreased from day 21 to day 28. Western blot analysis revealed that p-GSK3β (Ser 9) and GSK3β proteins were expressed at all time-points. The positive cells and protein expression ratio of p-GSK3β (Ser 9) against GSK3β increased from day 0 to day 14 and then decreased from day 14 to day 28. Finally, double-dye immunofluorescence assay revealed that p-GSK3β (Ser 9)-positive and RANKL-positive cells were co-localized around periapical lesions on days 14 and 28.

CONCLUSIONS

GSK3β and p-GSK3β (Ser 9) can be observed and may be involved in alveolar bone resorption and inflammatory response in periapical lesions, as well as associated with periapical lesion pathogenesis.

Transcriptome profiling of prostate tumor and matched normal samples by RNA-Seq

BACKGROUND

RNA-Sequencing (RNA-Seq) has greatly influenced cancer researches, and it provides an unprecedented resolution in estimating gene expression and has less signal noises compared to cDNA microarray.

AIM

We aimed to identify a list of protein-coding genes and lincRNAs that are expressed differentially between tumor and normal tissues.

MATERIALS AND METHODS

In this study, we analyzed including 10 human prostate tumor tissues and their matched normal tissues transcriptome dataset generated by recently developed RNA-Seq technology.

RESULTS

By aligning short reads to human RefSeq genes and lincRNAs, we identified 10 RefSeq genes that were differentially expressed between tumor and normal samples with a p-value < 0.05, which were sufficiently enough to distinguish these two groups. Further loosing the p-value cutoff to 0.1 identified an lincRNA which is antisense to Cullin-associated and neddulation-dissociated 1 (CAND1), whose expression is repressed in prostate tumor cells. By examining the expression of CAND1 and its antisense lincRNA in the transcriptome dataset, we found an interaction between them as high expression of CAND1 and low expression of lincRNA is normal samples, and verse visa in tumor samples.

CONCLUSIONS

These findings suggest the important usage of RNA-Seq in cancer studies for biomarker development and functional investigation.

NOD1 expression elicited by iE-DAP in first trimester human trophoblast cells and its potential role in infection-associated inflammation

OBJECTIVES

The underlying mechanisms of protective immunity of placental trophoblast cells against bacterial infection remain largely unknown. NOD1 are intracellular pattern recognition receptors that are activated by bacterial peptides and mediate innate immunity. This study aimed to investigate the expression and function of NOD1 in first trimester trophoblast cells, and evaluate the potential role of trophoblast cells in infection-associated inflammation.

STUDY DESIGN

Human extravillous trophoblast cell line HTR8 cells were stimulated with various concentrations of iE-DAP for various periods of time. NOD1 expression was detected by immunofluorescence, and the changes in NOD1 and RICK mRNA and protein in H8 cells were determined by real-time polymerase chain reaction and Western blot analysis. The concentrations of interleukin (IL)-8 and IL-6 secreted by H8 cells were examined by enzyme-linked immunosorbent assay. NF-κB transcription activity and P65 expression were detected by electrophoretic mobility shift assay and Western blot analysis.

RESULTS

H8 cells expressed NOD1, and the effects of iE-DAP on NOD1 were dose- and time-dependent. The concentration of IL-8 increased gradually with increasing concentration of iE-DAP, and the levels of IL-8 and IL-6 were associated with the duration of exposure to iE-DAP. The dose of iE-DAP was significantly associated with expression of RICK and P65, and stimulation of H8 cells by iE-DAP altered NF-κB transcription activity.

CONCLUSIONS

NOD1 may have a role in mediating infection-associated inflammation. Once iE-DAP is recognized by NOD1, the inflammatory response may be induced via NOD1-RICK-NF-κB-mediated pathways.

Expression of a cytokine, interleukin-23, in experimental periapical lesions

AIM

To investigate the expression of interleukin (IL)-23, a new member of the IL-12 family, in experimental periapical lesions.

METHODOLOGY

Periapical lesions were induced in Wistar rats by occlusal surface pulp exposure in mandibular first molars. The rats were randomly sacrificed 0, 7, 14, 21, 28, 35, 42 and 56 days after pulp exposure. The jaws that contained the first molars were obtained and routinely prepared for radiographic, histological, enzyme histochemical, immunohistochemical and double immunofluorescence analyses. Data were analysed by one-way analysis of variance and the Pearson correlation test.

RESULTS

The number of IL-23-positive cells increased from day 7 to day 35 and then gradually decreased. The number of osteoclasts increased and peaked on day 14 and then gradually decreased from day 21 to day 56. A significant positive correlation existed between the number of IL-23 positive cells and the size of bone resorption in periapical lesions from day 7 to day 56 (r = 0.875, P < 0.01).

CONCLUSIONS

Interleukin-23 can be observed and may be associated with inflammatory response and bone resorption in periapical lesions.

Comparison of spermatogenic damage induced at 6 months after ligation of the vas deferens at proximal and distal locations in the rabbit

Recent study in rabbits demonstrated that vasectomy via the inguinal canal did not result in any spermatogenic damage 3 months postoperation; this study aimed to determine whether the damage would occur in a longer term. The left or right vas deferens was ligated near the epididymal head (unilateral proximal vasectomy, 12 animals) or via the inguinal canal (unilateral distal vasectomy, 11 animals) in adult male rabbits, with a sham operation being performed on the contralateral side. Six months postoperation, testes, epididymides and vasa deferentia were removed and methacrylate resin-embedded sections prepared to evaluate spermatogenesis by histological (qualitative) and stereological (quantitative) studies. The juxta-epididymal segment of the occluded vas deferens was severely distended (filled with sperm) in 10 of the 11 animals with distal vasectomy and moderately or slightly distended in nine of the 12 animals with proximal vasectomy. Severe spermatogenic damage occurred in seven animals with proximal vasectomy (the juxta-epididymal vas moderately or slightly distended), in only one animal with distal vasectomy (the vas not severely distended). In conclusion, spermatogenic damage occurred at 6 months postvasectomy in some animals, especially those with proximal vasectomy and therefore shorter occluded reproductive tract for sperm storage; the damage was probably intra-tract pressure mediated.

The prevalence of and risk factors for non-carious cervical lesions in adults in Hubei Province, China

OBJECTIVES

To describe the prevalence of non-carious cervical lesions (NCCLs) and to assess the relative affects of risk factors on NCCLs in middle-aged and elderly people in Hubei Province, China.

DESIGN

A sample of 2,160 adults, aged 35-44 years and 65-74 years and balanced by age, gender, and urbanization, participated in the cross sectional epidemiological survey. Non-carious cervical lesions were examined using a modified Tooth Wear Index. Data were collected based on structured questionnaires that assessed general information as well as oral health.

RESULTS

The prevalence of non-carious cervical lesions was 38.8% for 35-44-year-olds and 56.6% for 65-74-year-olds. The first premolars, canines, and second premolars showed the highest prevalence of lesions, while the second molars demonstrated the least. Several risk factors such as age (OR = 2.45, p < 0.001), location (OR = 1.68, p = 0.001), frequency of toothbrushing (OR = 1.33, p = 0.016), bruxism (OR = 1.37, p < 0.001), and family income (OR = 1.44, p < 0.001) were found to be associated with lesion occurrence.

CONCLUSIONS

The prevalence of non-carious cervical lesions was relatively high in the middle-aged and elderly persons in China and was also associated with socio-behavioural risk factors.

Using Ascertainment for Targeted Resequencing to Increase Power to Identify Causal Variants

Researchers continue to use genome-wide association studies (GWAS) to find the genetic markers associated with disease. Recent studies have added to the typical two-stage analysis a third stage that uses targeted resequencing on a randomly selected subset of the cases to detect the causal single-nucleotide polymorphism (SNP). We propose a design for targeted resequencing that increases the power to detect the causal variant. The design features an ascertainment scheme wherein only those cases with the presence of a risk allele are selected for targeted resequencing. We simulated a disease with a single causal SNP to evaluate our method versus a targeted resequencing design using randomly selected individuals. The simulation studies showed that ascertaining individuals for the targeted resequencing can substantially increase the power to detect a causal SNP, without increasing the false-positive rate.

Effect of alendronate on alveolar bone resorption and angiogenesis in rats with experimental periapical lesions

AIM

To investigate the effects of systemically administered alendronate, one of the most potent bisphosphonates (BPs), on alveolar bone resorption and angiogenesis in rats subjected to experimental periapical lesions over two time periods.

METHODOLOGY

Forty adult Sprague-Dawley (SD) rats were divided equally into control and experimental groups, and the pulp chambers of mandibular first molars of all rats were exposed to the oral environment to induce periapical lesions. The experimental group received daily subcutaneous injections of alendronate at a dose of 0.25 mg kg(-1), whereas the control group received only the saline vehicle. These injections were initiated 1 week before the periapical lesion induction and then continued daily throughout the entire experimental period. After 2 or 4 weeks following pulp exposure, the rats were killed, and the mandibles were examined histologically for periapical bone loss area, number of microvascular vessels (NMV) and tartrate-resistant acid phosphatase (TRAP) activity.

RESULTS

Overall, periapical bone loss area and the number of TRAP-positive cells (osteoclasts) were significantly decreased at 2 and 4 weeks, respectively, after daily subcutaneous injection of alendronate compared with the control group (P < 0.05). There was no significant decrease change in NMV (P > 0.05).

CONCLUSIONS

Administration of alendronate to rats might inhibit alveolar bone resorption associated with periapical disease, which might not lead to impairment of angiogenesis. However, because of the differences between rats and humans, one has to consider the possible consequences of this treatment in the clinic.

Significance of perihematomal edema in acute intracerebral hemorrhage: the INTERACT trial

BACKGROUND

Uncertainty surrounds the effects of cerebral edema on outcomes in intracerebral hemorrhage (ICH).

METHODS

We used data from the INTERACT trial to determine the predictors and prognostic significance of "perihematomal" edema over 72 hours after ICH. INTERACT included 404 patients with CT-confirmed ICH and elevated systolic blood pressure (BP) (150-220 mm Hg) who had the capacity to commence BP lowering treatment within 6 hours of ICH. Baseline and repeat CT (24 and 72 hours) were performed using standardized techniques, with digital images analyzed centrally. Predictors of growth in edema were determined using generalized estimating equations, and its effects on clinical outcomes were estimated using a logistic regression model.

RESULTS

Overall, 270 patients had 3 sequential CT scans available for analyses. At baseline, there was a highly significant correlation between hematoma and perihematomal edema volumes (r(2) = 0.45). Lower systolic BP and baseline hematoma volume were independently associated with absolute increase in perihematomal edema volume. History of hypertension, baseline hematoma volume, and earlier time from onset to CT were independently associated with relative increase in edema volume. Both absolute and relative increases in perihematomal edema growth were significantly associated with death or dependency at 90 days after adjustment for age, gender, and randomized treatment, but not when additionally adjusted for baseline hematoma volume.

CONCLUSIONS

The degree of, and growth in, perihematomal edema are strongly related to the size of the underlying hematoma of acute intracerebral hemorrhage, and do not appear to have a major independent effect in determining the outcome from this condition.