Romidepsin Promotes Osteogenic and Adipocytic Differentiation of Human Mesenchymal Stem Cells through Inhibition of Histondeacetylase Activity.

Bone marrow mesenchymal stem cells (BMSCs) are adult multipotent stem cells that can differentiate into mesodermal lineage cells, including adipocytes and osteoblasts. However, the epigenetic mechanisms governing the lineage-specific commitment of BMSCs into adipocytes or osteoblasts are under investigation. Herein, we investigated the epigenetic effect of romidepsin, a small molecule dual inhibitor targeting HDAC1 and HDAC2 identified through an epigenetic library functional screen. BMSCs exposed to romidepsin (5 nM) exhibited enhanced adipocytic and osteoblastic differentiation. Global gene expression and signaling pathway analyses of differentially expressed genes revealed a strong enrichment of genes involved in adipogenesis and osteogenesis in romidepsin-treated BMSCs during induction into adipocytes or osteoblasts, respectively. Pharmacological inhibition of FAK signaling during adipogenesis or inhibition of FAK or TGFß signaling during osteogenesis diminished the biological effects of romidepsin on BMSCs. The results of chromatin immunoprecipitation combined with quantitative polymerase chain reaction indicated a significant increase in H3K9Ac epigenetic markers in the promoter regions of peroxisome proliferator-activated receptor gamma (PPARγ) and KLF15 (related to adipogenesis) or SP7 (Osterix) and alkaline phosphatase (ALP) (related to osteogenesis) in romidepsin-treated BMSCs. Our data indicated that romidepsin is a novel in vitro modulator of adipocytic and osteoblastic differentiation of BMSCs.

Papillon-Lefèvre syndrome: a series of five cases among siblings.

BACKGROUND: Papillon-Lefèvre syndrome is a rare autosomal recessive disorder characterized by palmoplantar hyperkeratosis and aggressively progressing periodontitis leading to premature loss of deciduous and permanent dentition. The etiopathogenesis of the syndrome is relatively obscure, and immunologic, genetic, or possible bacterial etiologies have been proposed. CASE PRESENTATION: A series of five cases of Papillon-Lefèvre syndrome among the siblings in a family is presented here: a 3-year-old Arab girl, a 4-year-old Arab boy, a 11-year-old Arab boy, a 12-year-old Arab boy, and a 14-year-old Arab boy. The patients presented with severe gingival inflammation and mobility of teeth. The clinical manifestations were typical of Papillon-Lefèvre syndrome and the degree of involvement of the oral and skin conditions varied among them. CONCLUSIONS: This case series stresses the consanguinity in the family as an etiologic factor. All siblings in the family were affected with Papillon-Lefèvre syndrome which makes this a rare case. A multidisciplinary approach with the active participation of a dental surgeon, dermatologist, and pediatrician is essential for the management of cases of Papillon-Lefèvre syndrome.

Association of Poly (ADP-Ribose) Polymerase 1 Variants with Oral Squamous Cell Carcinoma Susceptibility in a South Indian Population.

BACKGROUND: Oral cancers account for approximately 2% of all cancers diagnosed each year; however, the vast majority (80%) of the affected individuals are smokers whose risk of developing a lesion is five to nine times greater than that of non-smokers. Tobacco smoke contains numerous carcinogens that cause DNA damage, including oxidative lesions that are removed effectively by the base-excision repair (BER) pathway, in which poly (ADP-ribose) polymerase 1 (PARP-1), plays key roles. Genetic variations in the genes encoding DNA repair enzymes may alter their functions. Several studies reported mixed effects on the association between PARP-1 variants and the risk of cancer development. Till now no reported studies have investigated the association between PARP-1 variants and oral squamous cell carcinoma (OSCC) risk in an Indian population. MATERIALS AND METHODS: In the present case control study 100 OSCC patients and 100 matched controls were genotyped using PARP1 single nucleotide peptides (SNP's) rs1136410 and rs3219090 using TaqMan assays. RESULTS: The results indicated significantly higher risk with PARP1 rs1136410 minor allele "C" (OR=1.909; p=0.02942; CI, 1.060- 3.439). SNP rs1136410 also showed significantly increased risk in patients with smoking habit at C/C genotype and at minor allele C. CONCLUSIONS: The PAPR-1 Ala762Val polymorphism may play a role in progression of OSCC. Larger studies with a greater number of samples are needed to verify these findings.

Study of the Mechanical Properties of the Novel Zirconia-reinforced Glass lonomer Cement.

OBJECTIVES: The purpose of this in vitro study is to compare the compressive strength (CS) and diametral tensile strength (DTS) of the zirconia-reinforced restorative material (Zirconomer®) with conventional glass ionomers (Fuji 1X) and amalgam. MATERIALS AND METHODS: Specimens (n = 120) were fabricated from silver amalgam, reinforced glass ionomer cement (GIC) (glass ionomer, Fuji 1X GC Corp.), and zirconia-reinforced glass ionomer (Zirconomer, Shofu Inc.) for testing the CS and DTS. The results were analyzed using analysis of variance, followed by a Tukey post hoc test. RESULTS: Both CS and DTS were found to be significantly higher for the zirconia-reinforced GIC and silver amalgam compared with GIC (p < 0.001). CONCLUSION: A newer class of restorative material like Zirconomer helps to overcome the potential hazard of mercury, but retains the strength and durability of amalgam as well as the sustained high-fluoride release of GICs. Furthermore, long-term studies are required to confirm its use as an alternative to the currently available posterior restorative material.

Chemical Plaque Control Strategies in the Prevention of Biofilm-associated Oral Diseases.

Dental plaque is a biofilm that forms naturally on the surfaces of exposed teeth and other areas of the oral cavity. It is the primary etiological factor for the most frequently occurring oral diseases, such as dental caries and periodontal diseases. Specific, nonspecific, and ecologic plaque hypothesis explains the causation of dental and associated diseases. Adequate control of biofilm accumulation on teeth has been the cornerstone of prevention of periodontitis and dental caries. Mechanical plaque control is the mainstay for prevention of oral diseases, but it requires patient cooperation and motivation; therefore, chemical plaque control agents act as useful adjuvants for achieving the desired results. Hence, it is imperative for the clinicians to update their knowledge in chemical antiplaque agents and other developments for the effective management of plaque biofilm-associated diseases. This article explores the critical analysis of various chemical plaque control strategies and the current trends in the control and prevention of dental plaque biofilm.

Prevalence of anterior dental trauma and its associated factors among children aged 3-5 years in Jaipur City, India - A cross sectional study.

OBJECTIVE: To study the prevalence of anterior dental trauma and its associated factors among 800 preschool children aged 3 to 5 years in Jaipur City, Rajasthan, India. MATERIALS AND METHODS: A cross-sectional survey was conducted among children aged 3-5 years, who were enrolled in various private and public schools in Jaipur. Parents were asked to fill a form addressing socio-demographic data and clinical examinations were performed by a single dentist. Traumatic dental injuries (TDI) were assessed and recorded based on Andreasen's classification. Associated factors such as sex, socioeconomic status (SES), and the type of injury were also analyzed. The data were analyzed statistically using Statistical Package for the Social Sciences software (version 20). RESULTS: An overall 10.2% prevalence of TDI was observed among the study population. TDI were reported to be more among male children (11.87%) compared to female children (8.14%). Enamel fractures (69%) were the most prevalent type of anterior dental trauma. Upper central incisors were the most frequently affected. The SES of the parents had little influence on the prevalence of TDI. CONCLUSIONS: The prevalence rate of dental trauma among children aged 3-5 years was 10.2%. Associated factors, such as SES, were observed to be not significantly correlated to dental trauma among the studied preschoolers.

Isolation and Characterization of Nano-Hydroxyapatite from Salmon Fish Bone.

Nano-Hydroxyapatite (nHA) was isolated from salmon bone by alkaline hydrolysis. The resulting nHA was characterized using several analytical tools, including thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), to determine the purity of the nHA sample. The removal of organic matter from the raw fish was confirmed by TGA. FT-IR confirmed the presence of a carbonated group and the similarities to synthetic Sigma HA. XRD revealed that the isolated nHA was amorphous. Microscopy demonstrated that the isolated nHA possessed a nanostructure with a size range of 6-37 nm. The obtained nHA interacted with mesenchymal stem cells (MSCs) and was non-toxic. Increased mineralization was observed for nHA treated MSCs compared to the control group. These results suggest that nHA derived from salmon is a promising biomaterial in the field of bone tissue engineering.

Hepatocyte growth factor levels in the saliva and gingival crevicular fluid in smokers with periodontitis.

Hepatocyte growth factor (HGF) production by oral fibroblasts is enhanced by various molecules that are induced during inflammatory conditions including periodontitis. HGF plays an important role in the progression of periodontitis, by stimulating intense growth of epithelial cells and preventing regeneration of connective tissue attachments. Smokers have a greater risk factor in the pathogenesis and progression of periodontal disease. The objective of the study was to estimate the level of HGF in saliva and gingival crevicular fluid (GCF) in smokers with periodontitis and to compare these levels with that of nonsmokers with periodontitis and healthy controls. The HGF levels were found to be significantly high in the saliva and GCF of smokers with periodontitis compared to both never-smokers with periodontitis and the healthy control group. The elevated levels of HGF in the saliva and GCF in the study population could explain the intrinsic mechanism triggering the severity of the periodontitis in smokers. Further studies are necessary to validate the current observations and to establish a sensitive marker to predict periodontal disease activity.

The impact of chlorhexidine mouth rinse on the bond strength of polycarbonate orthodontic brackets.

OBJECTIVE: The purpose of the current in-vivo study was to assess the effect of using 0.12% chlorhexidine (CHX) mouth rinse, before bonding, on shear bond strength of polycarbonate brackets bonded with composite adhesive. SUBJECTS AND METHODS: Eighteen orthodontic patients with a mean age 21.41 ± 1.2 years, who were scheduled to have 2 or more first premolars extracted, were included in this study. Patients were referred for an oral prophylaxis program which included, in part, the use of a mouth rinse. Patients were divided into 2 groups, a test group of 9 patients who used 0.12% CHX gluconate mouth rinse twice daily and a control group of 9 patients who used a mouth rinse without CHX, but with same color. After 1 week, polycarbonate brackets were bonded to first premolars with Transbond XT composite adhesive. Premolars were extracted after 28 days and tested for shear bond strength on a universal testing machine. Student's t-test was used to compare shear bond strengths of both groups. RESULTS: No statistically significant difference was found in bond strengths' values between both groups. The test group (with CHX) has mean shear bond strength of 14.21 ± 2.42 MPa whereas the control group (without CHX) revealed a mean strength of 14.52 ± 2.31 MPa. CONCLUSION: The use of 0.12% CHX mouth rinse, for one week before bonding, did not affect the shear bond strength of polycarbonate brackets bonded with Transbond composite. Furthermore, these brackets showed clinically acceptable bond strength.