Osteocytic Sclerostin Expression in Alveolar Bone in Rats With Diabetes Mellitus and Ligature‐Induced Periodontitis

Background: Osteocytic sclerostin inhibits bone formation, and its expression is stimulated by tumor necrosis factor (TNF)‐α. This study investigates sclerostin and TNF‐α expression in rats with diabetes mellitus (DM) and periodontitis. Methods: Rats were divided into control (C), periodontitis (P), and DM + periodontitis (DP) groups. After induction of DM by streptozotocin, periodontitis was induced by ligature. At day 0 (control) and at days 3 and 20 after induction of periodontitis, alveolar bone, osteoclasts, osteoid area, and TNF‐α and sclerostin expression were evaluated. Results: The distance between the cemento‐enamel junction and the alveolar bone crest of the DP group was longer than that of the P group at day 20 after induction of periodontitis, but the number of osteoclasts was not different. Osteoid area decreased in both the P and DP groups by day 3, but whereas sustained osteoid suppression was observed in the DP group at day 20, osteoid formation was increased in the P group. The number of sclerostin‐positive osteocytes increased in both groups at day 3, but the increased number of sclerostin‐positive osteocytes was maintained only in the DP group through day 20. The number of TNF‐α–positive cells increased more in the DP group than in the P group. Conclusions: Enhanced alveolar bone loss, suppressed bone formation, and prevalent TNF‐α expression were characteristic of the DP group compared with the P group. Suppressed bone formation in the DP group was observed simultaneously with increased sclerostin and TNF‐α expression. These results suggest that upregulated osteocytic sclerostin expression in periodontitis accompanied by DM may play a role in suppressed bone formation.     

Prevalence of Gastroesophageal Reflux Disease Symptoms and Uninvestigated Dyspepsia in Korea: A Population-Based Study

Various reports on the prevalence of gastroesophageal reflux disease (GERD) and uninvestigated dyspepsia have been conducted in Western countries. We sought to determine the frequency of GERD symptoms and uninvestigated dyspepsia in Korea. Telephone interviews were conducted with 1,044 individuals. Of all subjects, 7.1% reported that GERD symptoms were present at least once a week, and 3.8% at least twice a week. The prevalence of heartburn according to educational level and acid regurgitation according to age was significantly different (P < 0.05). The prevalence of uninvestigated dyspepsia was reported as 12.2%. Dyspepsia was divided into subgroups of 34% ulcer-like, 56% dysmotility-like, and 10% nonspecific. The occurrence of dyspepsia did not vary according to age, gender, educational level and household income. As frequency of GERD symptoms increased, quality of life significantly decreased. We concluded that GERD symptoms and uninvestigated dyspepsia were prevalent in Korea. The prevalence was similar to that of other Asian countries.     

Contribution of Na+/H+ exchange to Na+ overload in the ischemic hypertrophied hyperthyroid rat heart

OBJECTIVE: The mechanisms responsible for intracellular ion homeostasis in ischemic hypertrophied myocardium are not fully known. Moderately hypertrophied hyperthyroid hearts (T3) are characterized by the bioenergetic changes and increased Na+/H+ exchange (NHE) activity comparable with those observed in humans and experimental models of hypertrophy. Here we test the hypothesis whether NHE inhibition in T3 heart improves ion homeostasis during ischemia and contractile function during recovery. METHODS: We compared intracellular H+ (H+i) and Na+ (Na+i) accumulations during 28 min global ischemia in isolated perfused T3 and euthyroid (EUT) rat hearts with and without NHE inhibition by using 31P and 23Na NMR. Heart function was measured during control perfusion and 30 min following ischemic insult. RESULTS: In T3 hearts ischemia caused: (1) faster and greater Na+i accumulation (534+/-25% of preischemic level versus 316+/-22% in EUT, P<0.001); (2) lower acidification (pH(i) 6.66+/-0.66 versus 6.12+/-0.12 in EUT, P<0.001); and (3) faster hydrolysis of ATP. NHE inhibition (amiloride 1 mM) in T3 hearts lead to: (1) delayed and lower Na+i accumulation by 35+/-5%; (2) faster and greater acidification (pH(i) 6.45+/-0.15, P<0.05); (3) delayed ATP degradation; and (4) improved heart function during recovery. When NHE was inhibited, all T3 hearts (n=11) recovered 68+/-10% of their preischemic rate pressure product (RPP), while only two untreated T3 hearts (from 11) recovered approximately 40% of preischemic RPP. CONCLUSIONS: These data suggest that NHE inhibition could be useful intervention for the prevention of ischemic/reperfusion cell injury and could improve the function of the hypertrophied heart after acute ischemia.     

Assessment of aldehyde dehydrogenase in viable cells

Cytosolic aldehyde dehydrogenase (ALDH), an enzyme responsible for oxidizing intracellular aldehydes, has an important role in ethanol, vitamin A, and cyclophosphamide metabolism. High expression of this enzyme in primitive stem cells from multiple tissues, including bone marrow and intestine, appears to be an important mechanism by which these cells are resistant to cyclophosphamide. However, although hematopoietic stem cells (HSC) express high levels of cytosolic ALDH, isolating viable HSC by their ALDH expression has not been possible because ALDH is an intracellular protein. We found that a fluorescent aldehyde, dansyl aminoacetaldehyde (DAAA), could be used in flow cytometry experiments to isolate viable mouse and human cells based on their ALDH content. The level of dansyl fluorescence exhibited by cells after incubation with DAAA paralleled cytosolic ALDH levels determined by Western blotting and the sensitivity of the cells to cyclophosphamide. Moreover, DAAA appeared to be a more sensitive means of assessing cytosolic ALDH levels than Western blotting. Bone marrow progenitors treated with DAAA proliferated normally. Furthermore, marrow cells expressing high levels of dansyl fluorescence after incubation with DAAA were enriched for hematopoietic progenitors. The ability to isolate viable cells that express high levels of cytosolic ALDH could be an important component of methodology for identifying and purifying HSC and for studying cyclophosphamide-resistant tumor cell populations.     

The strength of combined cytogenetic and mate-pair sequencing techniques illustrated by a germline chromothripsis rearrangement involving FOXP2

Next-generation mate-pair sequencing (MPS) has revealed that many constitutional complex chromosomal rearrangements (CCRs) are associated with local shattering of chromosomal regions (chromothripsis). Although MPS promises to identify the molecular basis of the abnormal phenotypes associated with many CCRs, none of the reported mate-pair sequenced complex rearrangements have been simultaneously studied with state-of-the art molecular cytogenetic techniques. Here, we studied chromothripsis-associated CCR involving chromosomes 2, 5 and 7, associated with global developmental and psychomotor delay and severe speech disorder. We identified three truncated genes: CDH12, DGKB and FOXP2, confirming the role of FOXP2 in severe speech disorder, and suggestive roles of CDH12 and/or DGKB for the global developmental and psychomotor delay. Our study confirmes the power of MPS for detecting breakpoints and truncated genes at near nucleotide resolution in chromothripsis. However, only by combining MPS data with conventional G-banding and extensive fluorescence in situ hybridizations could we delineate the precise structure of the derivative chromosomes.     

Common genetic variants do not associate with CAD in familial hypercholesterolemia

In recent years, multiple loci dispersed on the genome have been shown to be associated with coronary artery disease (CAD). We investigated whether these common genetic variants also hold value for CAD prediction in a large cohort of patients with familial hypercholesterolemia (FH). We genotyped a total of 41 single-nucleotide polymorphisms (SNPs) in 1701 FH patients, of whom 482 patients (28.3%) had at least one coronary event during an average follow up of 66 years. The association of each SNP with event-free survival time was calculated with a Cox proportional hazard model. In the cardiovascular disease risk factor adjusted analysis, the most significant SNP was rs1122608:G>T in the SMARCA4 gene near the LDL-receptor (LDLR) gene, with a hazard ratio for CAD risk of 0.74 (95% CI 0.49–0.99; P-value 0.021). However, none of the SNPs reached the Bonferroni threshold. Of all the known CAD loci analyzed, the SMARCA4 locus near the LDLR had the strongest negative association with CAD in this high-risk FH cohort. The effect is contrary to what was expected. None of the other loci showed association with CAD.     

Clinical approaches to non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease(NAFLD)ranges from simple steatosis to nonalcoholic steatohepatitis(NASH),leading to fibrosis and potentially cirrhosis,and it is one of the most common causes of liver disease worldwide.NAFLD is associated with other medical conditions such as metabolic syndrome,obesity,cardiovascular disease and diabetes.NASH can only be diagnosed through liver biopsy,but noninvasive techniques have been developed to identify patients who are most likely to have NASH or fibrosis,reducing the need for liver biopsy and risk to patients.Disease progression varies between individuals and is linked to a number of risk factors.Mechanisms involved in the pathogenesis are associated with diet and lifestyle,influx of free fatty acids to the liver from adipose tissue due to insulin resistance,hepatic oxidative stress,cytokines production,reduced very low-density lipoprotein secretion and intestinal microbiome.Weight loss through improved diet and increased physical activity has been the cornerstone therapy of NAFLD.Recent therapies such as pioglitazone and vitamin E have been shown to be beneficial.Omega 3 polyunsaturated fatty acids and statins may offer additional benefits.Bariatric surgery should be considered in morbidly obese patients.More research is needed to assess the impact of these treatments on a long-term basis.The objective of this article is to briefly review the diagnosis,management and treatment of this disease in order to aid clinicians in managing these patients.     

Comparing human and mouse salivary glands: A practice guide for salivary researchers

Mice are a widely utilized in vivo model for translational salivary gland research but must be used with caution. Specifically, mouse salivary glands are similar in many ways to human salivary glands (i.e., in terms of their anatomy, histology, and physiology) and are both readily available and relatively easy and affordable to maintain. However, there are some significant differences between the two organisms, and by extension, the salivary glands derived from them must be taken into account for translational studies. The current review details pertinent similarities and differences between human and mouse salivary glands and offers practical guidelines for using both for research purposes.