Identification of copy neutral loss of heterozygosity on chromosomes 1p, 1q, and 6p among nonsyndromic cleft lip and/or without cleft palate with hypodontia

BACKGROUND

Nonsyndromic cleft lip and/or without cleft palate (NSCL/P) with or without hypodontia is a common developmental aberration in humans and animals. This study aimed to identify the loss of heterozygosity (LOH) involved in hypodontia and NSCL/P pathogenesis.

METHODS

This is a cross-sectional study that conducted genome-wide copy number analysis using CytoScan 750K array on salivary samples from Malay subjects with NSCL/P with or without hypodontia aged 7-13 years. To confirm the significant results, simple logistic regression was employed to conduct statistical data analysis using SPSS software.

RESULTS

The results indicated the most common recurrent copy neutral LOH (cnLOH) observed at 1p33-1p32.3, 1q32.2-1q42.13 and 6p12.1-6p11.1 loci in 8 (13%), 4 (7%), and 3 (5%) of the NSCL/P subjects, respectively. The cnLOHs at 1p33-1p32.3 (D1S197), 1q32.2-1q42.13 (D1S160), and 6p12.1-6p11.1 (D1S1661) were identified observed in NSCL/P and noncleft children using microsatellite analysis markers as a validation analysis. The regions affected by the cnLOHs at 1p33-1p32.3, 1q32.2-1q42.13, and 6p12.1-6p11.1 loci contained selected genes, namely FAF1, WNT3A and BMP5, respectively. There was a significant association between the D1S197 (1p33-32.3) markers containing the FAF1 gene among NSCL/P subjects with or without hypodontia compared with the noncleft subjects (p-value = 0.023).

CONCLUSION

The results supported the finding that the genetic aberration on 1p33-32.3 significantly contributed to the development of NSCL/P with or without hypodontia. These results have an exciting prospect in the promising field of individualized preventive oral health care.

Prevalence of GP. Mur variant phenotype among Malaysian blood donors

BACKGROUND AND OBJECTIVE

A number of glycophorin variant phenotypes or hybrid glycophorin variants of the MNS blood group system bear multiple immunogenic antigens such as Mia, Mur, and MUT. In the East and Southeast Asian populations, glycoprotein (GP.) Mur is the most common glycophorin variant phenotype expressing those three immunogens. The aim of this study was to detect MNS system glycophorin variant phenotypes (GP. Mur, GP. Hop, GP. Bun, GP. HF, and GP. Hut) among Malaysian blood donors.

MATERIALS AND METHODS

In this cross-sectional study, 144 blood donors were selected under stratified random sampling. The deoxyribonucleic acid was extracted from whole blood samples, followed by a polymerase chain reaction assay. Sanger sequencing was used to identify the specific MNS variants and then validated by a serological crossmatch with known anti-Mur and anti-MUT.

RESULTS

GP. Mur was identified among Malaysian blood donors with a prevalence of 6.94%, and no other variants of the MNS system were found.

CONCLUSION

The present study substantiates that GP. Mur is the main variant of the MNS system glycophorin (B-A-B) hybrid in Malaysian blood donors. GP. Mur-negative red blood cells must therefore be considered in the current transfusion policy in order to prevent alloimmunization and immune-mediated transfusion reactions, particularly in transfusion-dependent patients.

Growth Factor Cocktail to Facilitate Epithelial Differentiation of Exfoliated Deciduous Teeth Stem Cells

Epithelial cells are important in the regeneration of oral mucosal tissue. The cell source is commonly derived from tissue biopsy, which is obtained through surgery. Stem cells from human exfoliated deciduous teeth (SHED) were demonstrated to differentiate into multiple cell types. As it can be readily available from exfoliated deciduous teeth, it can be induced and become a potential source of epithelial cell for oral tissue study. This study aims to examine a mixture of growth factors in the differentiation of epithelial-like cells obtained from human exfoliated deciduous teeth (SHED) stem cells. This growth factor cocktail constitutes hepatocyte growth factor (HGF), keratinocyte growth factor (KGF), insulin-like growth factor 2 (IGF-II), and epidermal growth factor (EGF). After introducing the cocktail, the treated SHED were assessed for epithelial characteristics and markers using cell proliferation test, morphological transformation, protein and gene expression by immunofluorescence staining and cytometry assessment, respectively. The proliferation rate was analysed statistically using Analysis of Variance (ANOVA) with Repeated Measures (p<0.05). SHED cells demonstrated morphological changes on the 7th day after using the cocktail. These transformations are in alignment with the identification of genes associated with epithelial cells and positive stain outcomes for pan-cytokeratin, E-cadherin, and p63. The cell proliferation test indicated that proliferation of cells and growth factor introduction were significantly correlated. The growth factor cocktail used for this research facilitated SHED differentiation for epithelial-like cells. The outcomes validate the production of epithelial cells using SHED; tissue production studies focus on these aspects immensely.

Analysis of Ionic-Exchange of Selected Elements between Novel Nano-Hydroxyapatite-Silica Added Glass Ionomer Cement and Natural Teeth

One of the foremost missions in restorative dentistry is to discover a suitable material that can substitute lost and damaged tooth structure. To this date, most of the restorative materials utilized in dentistry are bio-inert. It is predicted that the addition of nano-HA-SiO₂ to GIC matrix could produce a material with better ion-exchange between the restorative material and natural teeth. Therefore, the aim of the current study was to synthesize and investigate the transfer of specific elements (calcium, phosphorus, fluoride, silica, strontium, and alumina) between nano-hydroxyapatite-silica added GIC (nano-HA-SiO₂-GIC) and human enamel and dentine. The novel nano-hydroxyapatite-silica (nano-HA-SiO₂) was synthesized using one-pot sol-gel method and added to cGIC. Semi-quantitative energy dispersive X-ray (EDX) analysis was carried out to determine the elemental distribution of fluorine, silicon, phosphorus, calcium, strontium, and aluminum. Semi-quantitative energy dispersive X-ray (EDX) analysis was performed by collecting line-scans and dot-scans. The results of the current study seem to confirm the ionic exchange between nano-HA-SiO₂-GIC and natural teeth, leading to the conclusion that increased remineralization may be possible with nano-HA-SiO₂-GIC as compared to cGIC (Fuji IX).

Identification of Copy Number Variation Among Nonsyndromic Cleft Lip and or Without Cleft Palate With Hypodontia: A Genome-Wide Association Study

Nonsyndromic cleft lip and or without cleft palate (NSCL/P) with the hypodontia is a common developmental abnormality in humans and animals. This study identified the genetic aberration involved in both NSCL/P and hypodontia pathogenesis. A cross-sectional study using genome-wide study copy number variation-targeted CytoScan 750K array carried out on salivary samples from 61 NSCL/P and 20 noncleft with and without hypodontia Malay subjects aged 7-13 years old. Copy number variations (CNVs) of SKI and fragile histidine triad (FHIT) were identified in NSCL/P and noncleft children using quantitative polymerase chain reaction (qPCR) as a validation analysis. Copy number calculated (CNC) for each gene determined with Applied Biosystems CopyCaller Software v2.0. The six significant CNVs included gains (12q14.3, 15q26.3, 1p36.32, and 1p36.33) and losses (3p14.2 and 4q13.2) in NSCL/P with hypodontia patients compared with the NSCL/P only. The genes located in these regions encoded LEMD3, IGF1R, TP73, SKI, FHIT, and UGT2β15. There were a significant gain and loss of both SKI and FHIT copy number in NSCL/P with hypodontia compared with the noncleft group (p < 0.05). The results supported that CNVs significantly furnish to the development of NSCL/P with hypodontia.

Amniotic Membrane Enhance the Effect of Vascular Endothelial Growth Factor on the Angiogenic Marker Expression of Stem Cells from Human Exfoliated Deciduous Teeth

Previously, it was reported that human amniotic membrane (AM) induced stem cells from human deciduous exfoliated teeth (SHED) endothelial-like-cell differentiation. This interesting effect of AM matrix on SHED demands further elucidation. Objective of this in vitro work was to study the effect of 24-h VEGF induced on SHED endothelial differentiation when seeded on acellular stromal side (SS) of AM matrix. Stemness of SHED was identified by flow cytometry. Cell attachment and morphological changes towards the matrix was observed by scanning electron microscopy. Protein expression of endothelial marker was examined by Western blot. The expression of stem cells and endothelial-specific gene markers of VEGF-induced SHED cultured on human AM was inspected via reverse transcriptase-polymerase chain reaction. Results showed SHED at both passages retain stemness property. Ang-1 protein was expressed in SHED. Cells treated with VEGF and cultured on AM transformed attached well to AM. VEGF-induced SHED expressed both stem cell and endothelial-specific markers throughout the treatments and timeline. Interestingly, prolonged VEGF treatment increased the expression of Cox-2 and VE-Cadherin genes in all treated groups when compared to SHED. It was concluded that the VEGF-induced SHED showed better expression of endothelial-specific markers when cultured on SS of AM, with prolonged VEGF treatment.

Modifications of Glass Ionomer Cement Powder by Addition of Recently Fabricated Nano-Fillers and Their Effect on the Properties: A Review

The aim of this article is to provide a brief insight regarding the recent studies and their recommendations related to the modifications to glass ionomer cement (GIC) powder in order to improve their properties. An electronic search of publications was made from the year 2000 to 2018. The databases included in the current study were EBSCOhost, PubMed, and ScienceDirect. The inclusion criteria for the current study include publication with abstract or full-text articles, original research, reviews or systematic reviews, in vitro, and in vivo studies that were written in English language. Among these only articles published in peer-reviewed journals were included. Articles published in other languages, with no available abstract and related to other nondentistry fields, were excluded. A detailed review of the recent materials used as a filler phase in GIC powder has revealed that not all modifications produce beneficial results. Recent work has demonstrated that modification of GIC powder with nano-particles has many beneficial effects on the properties of the material. This is due to the increase in surface area and surface energy, along with better particle distribution of the nano-particle. Therefore, more focus should be given on nano-particle having greater chemical affinity for GIC matrix as well as the tooth structure that will enhance the physicochemical properties of GIC.

The Biological Evaluation of Conventional and Nano-Hydroxyapatite-Silica Glass Ionomer Cement on Dental Pulp Stem Cells: A Comparative Study

BACKGROUND

Despite their lower strength, glass ionomer cements (GICs) are widely used as restorative materials because of their anti-cariogenic properties, direct adhesion to tooth structure and good biocompatibility. Recently, the addition of nano-hydroxyapatite (nano-HA)-silica to conventional GIC (cGIC) has been shown to improve the strength of cGIC. However, the biocompatibility and cell attachment properties of this material are unknown.

AIMS

This study aims to evaluate and compare the cytotoxicity and cell attachment properties of cGIC and nano-HA-silica-GIC on dental pulp stem cells (DPSCs).

METHODS AND MATERIALS

Material extracts of nano-HA-silica-GIC and cGIC were prepared into seven serial dilutions and applied to 96 well plates seeded with DPSCs. After 72 h, the cell viability was determined using MTT assay. The DPSCs cell attachment properties were examined under scanning electron microscope (SEM) after 24 and 72 h. Kruskal-Wallis test was used to analyse the data for MTT assay (P < 0.05). SEM images of cell attachment properties were also described.

RESULTS

Nano-HA-silica-GIC and cGIC was shown to be slight to non-cytotoxic at all concentrations, except 200 mg/ml. Moderate cytotoxicity has been observed at 200 mg/ml concentration where nano-HA-silica-GIC and cGIC revealed cell viability values of 44.38 and 42.15%, respectively. Nano-HA-silica-GIC demonstrated better cell viability values than cGIC at all concentrations except for 6.25 and 12.5 mg/ml. Nevertheless, the results were not statistically significant (P > 0.05). SEM examination revealed the increasing numbers of DPSCs attached to both groups with prominent filopodia, especially after 72 h.

CONCLUSIONS

Nano-HA-silica-GIC exhibited good biocompatibility which is comparable to cGIC and favoured the attachment of DPSCs.

The synergistic effects of IL-6/IL-17A promote osteogenic differentiation by improving OPG/RANKL ratio and adhesion of MC3T3-E1 cells on hydroxyapatite

OBJECTIVE

In this study, we evaluated the potential role of IL-6 and/or IL-17A in regulating the OPG/RANKL (osteoprotegerin/receptor activator of nuclear factor kappa b ligand) system of murine osteoblast cell line (MC3T3-E1) cultured on hydroxyapatite (HA).

METHODS

MC3T3-E1 cells were seeded on HA and treated with recombinant IL-6 or rIL-17A or combination of the two cytokines. Cell proliferation and differentiation activity were measured by MTS and alkaline phosphatase assays respectively. Observation of cell adhesion and proliferation was examined by scanning electron microscopy. Gene and protein expressions were performed on RANKL and OPG using qPCR, Western blot and ELISA.

RESULTS

We demonstrated that treatment with recombinant IL-17A (rIL-17A) and the combination rIL-6/rIL-17A promoted better adhesion and higher proliferation of cells on HA. Cells treated with rIL-17A and the combination cytokines showed a significant increase in differentiation activity on day 7, 10 and 14 as indicated by ALP activity (p < 0.001). Gene and protein expressions showed significant up-regulation of OPG and ALP (p < 0.001) and down-regulation of RANKL (p < 0.001) expression by all the treated groups. Interestingly, the combination of the two cytokines resulted in a significant increase of OPG/RANKL ratio (p < 0.001).

CONCLUSION

These findings indicated that treatment with the combination of the two cytokines (IL-6/IL-17A) has synergistic effects to promote osteoblastic differentiation but suppress osteoclastogenesis by altering the OPG/RANKL ratio.

Angiogenic and osteogenic potentials of dental stem cells in bone tissue engineering

Manipulation of dental stem cells (DSCs) using current technologies in tissue engineering unveil promising prospect in regenerative medicine. DSCs have shown to possess angiogenic and osteogenic potential in both in vivo and in vitro. Neural crest derived DSCs can successfully be isolated from various dental tissues, exploiting their intrinsic great differentiation potential. In this article, researcher team intent to review the characteristics of DSCs, with focus on their angiogenic and osteogenic differentiation lineage. Clinical data on DSCs are still lacking to prove their restorative abilities despite extensive contemporary literature, warranting research to further validate their application for bone tissue engineering.

Study On Flaxseed Crude Extract On Stem Cells From Human Exfoliated Deciduous Teeth (SHED)

Introduction: Flaxseeds offer a wide range of pharmacological properties including antioxidant, antibacterial and anticancer. However its effect on mesenchymal stem cells has not been elucidated. Thus, this study aimed to determine the effects of flaxseed crude extract on stem cell from human exfoliated deciduous teeth (SHED) in terms of cell viability, morphology and proliferation activity. Materials and Methods: Whole flaxseeds were ground and extracted with absolute ethanol using soxhlet extractor. The effects of flaxseed on SHED were assessed for cell viability using MTT assay, cell morphology using inverted microscope and proliferative activity describe as population doubling time (PDT) using alamar Blue assay. Fatty acid composition of flaxseed was analysed using gas chromatography-mass spectrometry (GCMS) instrumental technique. Results: The effects of flaxseed on SHED were observed to be dose-dependent, where higher concentration of the extract resulted in lower cell viability. The concentration of the flaxseed required to inhibit 50% of cell viability (IC50) was 10.56±0.22 mg/ml. Morphological observation demonstrated that flaxseed altered the cell morphology at concentration above 8 mg/ml. Based on alamarBlue assay, SHED treated with flaxseed at concentration 0.5, 1, 2, 4, 8, 10.56 mg/ml showed no significant difference of PDT when compared to control (p>.05). GCMS analysis revealed the presence of linolenic acid as major compound, linoleic acid and palmitic acid and oleic acid. Conclusion(s): Crude extract of flaxseed at concentration below 8 mg/ml may be applied in the future study of SHED. The linolenic acid in flaxseed may have been responsible for the cell viability and proliferation activity of SHED.

Biological Interaction Between Human Gingival Fibroblasts and Vascular Endothelial Cells for Angiogenesis: A Co-culture Perspective

Advancement in cell culture protocols, multidisciplinary research approach, and the need of clinical implication to reconstruct damaged or diseased tissues has led to the establishment of three-dimensional (3D) test systems for regeneration and repair. Regenerative therapies, including dental tissue engineering, have been pursued as a new prospect to repair and rebuild the diseased/lost oral tissues. Interactions between the different cell types, growth factors, and extracellular matrix components involved in angiogenesis are vital in the mechanisms of new vessel formation for tissue regeneration. In vitro pre-vascularization is one of the leading scopes in the tissue-engineering field. Vascularization strategies that are associated with co-culture systems have proved that there is communication between different cell types with mutual beneficial effects in vascularization and tissue regeneration in two-dimensional or 3D cultures. Endothelial cells with different cell populations, including osteoblasts, smooth muscle cells, and fibroblasts in a co-culture have shown their ability to advocate pre-vascularization. In this review, a co-culture perspective of human gingival fibroblasts and vascular endothelial cells is discussed with the main focus on vascularization and future perspective of this model in regeneration and repair.

White mineral trioxide aggregate mixed with calcium chloride dihydrate: chemical analysis and biological properties

OBJECTIVES

This study aimed to evaluate the chemical and biological properties of fast-set white mineral trioxide aggregate (FS WMTA), which was WMTA combined with calcium chloride dihydrate (CaCl₂·2H₂O), compared to that of WMTA.

MATERIALS AND METHODS

Surface morphology, elemental, and phase analysis were examined using scanning electron microscope (SEM), energy dispersive X-ray microanalysis (EDX), and X-ray diffraction (XRD), respectively. The cytotoxicity and cell attachment properties were evaluated on human periodontal ligament fibroblasts (HPLFs) using methyl-thiazol-diphenyltetrazolium (MTT) assay and under SEM after 24 and 72 hours, respectively.

RESULTS

Results showed that the addition of CaCl₂·2H₂O to WMTA affected the surface morphology and chemical composition. Although FS WMTA exhibited a non-cytotoxic profile, the cell viability values of this combination were lesser than WMTA, and the difference was significant in 7 out of 10 concentrations at the 2 time intervals (p < 0.05). HPLFs adhered over the surface of WMTA and at the interface, after 24 hours of incubation. After 72 hours, there were increased numbers of HPLFs with prominent cytoplasmic processes. Similar findings were observed with FS WMTA, but the cells were not as confluent as with WMTA.

CONCLUSIONS

The addition of CaCl₂·2H₂O to WMTA affected its chemical properties. The favorable biological profile of FS WMTA towards HPLFs may have a potential impact on its clinical application for repair of perforation defects.

Immunomodulatory Effect of Cytokines in the Differentiation of Mesenchymal Stem Cells: A Review

Mesenchymal stem cells (MSCs) are stromal origin cells with multilineage differentiation capacity. The immunoregulatory properties of MSCs can be interfered effectively by cytokines. Cytokines, produced by a broad range of cells, act at the systemic level to influence biological phenomena such as inflammation, wound healing, organogenesis and oncogenesis. Cytokines also play vital roles in the differentiation of MSCs into several cell lineages. This review summarizes on how cytokines can affect MSCs differentiation and their relative signaling pathways, which may serve to understand the possible underlying mechanisms. Also, this review reveals the potential clinical use of MSCs as promising therapeutic agents due to their special characteristics such as multipotent differentiation, immunomodulatory properties, and selfrestoration.

Properties of Cell Sources in Tissue-Engineered Three-dimensional Oral Mucosa Model: A Review

Oral mucosa is a mucous membrane lining the oral cavity. Its main function is to protect the deeper structures against the external factors; thermal, chemical, mechanical and biological stimuli. Apart from that, it also plays a significant role during mastication, deglutition and speech. Some oral diseases or injuries to oral mucosa lead to impairment of the oral functions and aesthetics which eventually result in permanent defect of oral mucosa. In order to overcome this defect, different approaches for the development of reconstructed oral mucosa models have been employed including skin/autologous grafts, guided tissue replacement, vestibuloplasty etc. However, the finding of an acceptable source for the transplantations or autologous grafts seems a bit challenging. To overcome this problem, the development of oral mucosa using tissue engineering approach has been widely studied involving various cell lines from different sources. This paper aims to highlight various cell sources used in the development of tissueengineered oral mucosa models based on articles retrieved from PubMed and MEDLINE databases using the search terms "oral mucosa tissue engineering", regardless of time when published.

Chemical analysis and biological properties of two different formulations of white portland cements

White Portland cement (WPC) has generated research interests in the field of endodontics. This study compared between the properties of two formulations of white Portland cement (WPC) of different origin (Malaysia [MA] and Egypt [EG]). WPCs with and without calcium chloride dihydrate were prepared. Scanning electron microscope (SEM), energy dispersive X-ray micro-analysis, and X-ray diffraction were used for surface morphology evaluation, elemental, and phase analysis, respectively. After the preparation of optimized serial dilutions, the cytotoxicity was evaluated on human periodontal ligament fibroblasts (HPLFs) and dental pulp stem cells (DPSCs) using methyl-thiazol-diphenyltetrazolium assay after 24 and 72 h. Cell attachment properties were examined under SEM after 24 and 72 h. Results showed that the surface morphology and chemical composition of both formulations demonstrated detectable variations. The cytotoxicity evaluation showed different cellular responses of HPLFs compared to DSPCs. Both formulations favored the viability of HPLFs. However, the fast set formulations demonstrated severe cytotoxicity on DPSCs. Significant differences between EGWPC and MAWPC were identified (p < 0.05). The cell attachment properties were favorable; however, HPLFs attached and spread over the samples better than DPSCs. In conclusion, WPC of different origin may show differences in chemical and biological properties. The addition of CaCl2 ·2H2 O to WPC can affect its properties. Human cell types may react differently towards different formulations of WPCs. SCANNING 38:303-316, 2016. © 2015 Wiley Periodicals, Inc.

Angiogenic potential of extracellular matrix of human amniotic membrane

Combination between tissue engineering and other fields has brought an innovation in the area of regenerative medicine which ultimate aims are to repair, improve, and produce a good tissue construct. The availability of many types of scaffold, both synthetically and naturally have developed into many outstanding end products that have achieved the general objective in tissue engineering. Interestingly, most of this scaffold emulates extracellular matrix (ECM) characteristics. Therefore, ECM component sparks an interest to be explored and manipulated. The ECM featured in human amniotic membrane (HAM) provides a suitable niche for the cells to adhere, grow, proliferate, migrate and differentiate, and could possibly contribute to the production of angiogenic micro-environment indirectly. Previously, HAM scaffold has been widely used to accelerate wound healing, treat bone related and ocular diseases, and involved in cardiovascular repair. Also, it has been used in the angiogenicity study, but with a different technical approach. In addition, both side of HAM could be used in cellularised and decellularised conditions depending on the objectives of a particular research. Therefore, it is of paramount importance to investigate the behavior of ECM components especially on the stromal side of HAM and further explore the angiogenic potential exhibited by this scaffold.

Effects of Perivitelline Fluid Obtained from Horseshoe Crab on The Proliferation and Genotoxicity of Dental Pulp Stem Cells

Objective

Perivitelline fluid (PVF) of the horseshoe crab embryo has been reported to possess an important role during embryogenesis by promoting cell proliferation. This study aims to evaluate the effect of PVF on the proliferation, chromosome aberration (CA) and mutagenicity of the dental pulp stem cells (DPSCs).

Materials and Methods

This is an in vitro experimental study. PVF samples were collected from horseshoe crabs from beaches in Malaysia and the crude extract was prepared. DPSCs were treated with different concentrations of PVF crude extract in an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay (cytotoxicity test). We choose two inhibitory concentrations (IC₅₀ and IC₂₅) and two PVF concentrations which produced more cell viability compared to a negative control (100%) for further tests. Quantitative analysis of the proliferation activity of PVF was studied using the AlamarBlue®assay for 10 days. Population doubling times (PDTs) of the treatment groups were calculated from this assay. Genotoxicity was evaluated based on the CA and Ames tests. Statistical analysis was carried out using independent t test to calculate significant differences in the PDT and mitotic indices in the CA test between the treatment and negative control groups. Significant differences in the data were P<0.05.

Results

A total of four PVF concentrations retrieved from the MTT assay were 26.887 mg/ml (IC₅₀), 14.093 mg/ml (IC₂₅), 0.278 mg/ml (102% cell viability) and 0.019 mg/ml (102.5% cell viability). According to the AlamarBlue®assay, these PVF groups produced comparable proliferation activities compared to the negative (untreated) control. PDTs between PVF groups and the negative control were insignificantly different (P>0.05). No significant aberrations in chromosomes were observed in the PVF groups and the Ames test on the PVF showed the absence of significant positive results.

Conclusion

PVF from horseshoe crabs produced insignificant proliferative activity on treated DPSCs. The PVF was non-genotoxic based on the CA and Ames tests.

Screening of Transforming Growth Factor Beta 3 and Jagged2 Genes in the Malay Population with Nonsyndromic Cleft Lip with or without Cleft Palate

Objective

To determine the prevalence of mutations in transforming growth factor beta 3 (TGFβ3) and Jagged2 genes and their association with nonsyndromic cleft lip with or without cleft palate (CL±P) patients.

Design

Cross-sectional study on nonsyndromic CL±P and noncleft patients.

Setting

Reconstructive clinic and outpatient dental clinic, Hospital Universiti Sains Malaysia.

Patients

Blood samples of 96 nonsyndromic CL±P and 96 noncleft subjects.

Main Outcome Measure

Prevalence and association of mutations in TGFβ3 and Jagged2 genes with nonsyndromic CL±P.

Results

Most of the nonsyndromic CL±P patients (53.1%) had left unilateral CLP. There were slightly more females (56.6%) compared with males. The prevalence of the mutations in the TGFβ3 gene was 17.7% (95% confidence interval [CI]: 9.5, 24.5) and in the Jagged2 gene was 12.5% (95% CI: 5.5, 18.5), which was higher compared with the noncleft group. For the TGFβ3 gene, there was no mutation in the coding region in either of the groups. All variants were single nucleotide polymorphisms located within the intronic flanking region. Two variants were identified (g.15812T>G and g.15966A>G) in both nonsyndromic CL±P and noncleft patients. However, the association was not significant ( P > .05). Three variants (g.19779C>T, g.19547G>A, and g.19712C>T) were identified in the Jagged2 gene among nonsyndromic CL±P and noncleft patients. Only g.19712C>T showed a significant association with nonsyndromic CL±P patients ( P = .039).

Conclusion

g.19712C>T might play a crucial role in the development of cleft lip and palate. To the best of our knowledge, this is the first report of the mutation found within intron 13 of the Jagged2 gene among nonsyndromic CL±P Malay patients.

The relationship between telomere length and beekeeping among Malaysians

The belief that beekeepers live longer than anyone else is present since ages. However, no research has been done to explore the longevity of life in beekeepers. Here, we investigated the telomere length in 30 male beekeepers and 30 male non-beekeepers and associated them with the longevity of life using Southern analysis of terminal restriction fragments (TRFs) generated by Hinf I/Rsa I digestion of human genomic DNA using TeloTAGGG Telomere Length Assay. Interestingly, we found that the telomere length of male beekeepers was significantly longer than those of male non-beekeepers with a p value of less than 0.05, suggesting that beekeepers may have longer life compared to non-beekeepers. We further found that the consumption of bee products for a long period and frequent consumption of bee products per day are associated with telomere length. An increase of year in consuming bee products is associated with a mean increase in telomere length of 0.258 kbp. In addition, an increase in frequency of eating bee products per day was also associated with a mean increase of 2.66 kbp in telomere length. These results suggested that bee products might play some roles in telomere length maintenance.

A Comparison of Culture Characteristics between Human Amniotic Mesenchymal Stem Cells and Dental Stem Cells

In the past decade, the field of stem cell biology is of major interest among researchers due to its broad therapeutic potential. Stem cells are a class of undifferentiated cells that are able to differentiate into specialised cell types. Stem cells can be classified into two main types: adult stem cells (adult tissues) and embryonic stem cells (embryos formed during the blastocyst phase of embryological development). This review will discuss two types of adult mesenchymal stem cells, dental stem cells and amniotic stem cells, with respect to their differentiation lineages, passage numbers and animal model studies. Amniotic stem cells have a greater number of differentiation lineages than dental stem cells. On the contrary, dental stem cells showed the highest number of passages compared to amniotic stem cells. For tissue regeneration based on animal studies, amniotic stem cells showed the shortest time to regenerate in comparison with dental stem cells.

Effect of different calcium phosphate scaffold ratios on odontogenic differentiation of human dental pulp cells

Calcium phosphate (CaP) scaffolds have been widely and successfully used with osteoblast cells for bone tissue regeneration. However, it is necessary to investigate the effects of these scaffolds on odontoblast cells' proliferation and differentiation for dentin tissue regeneration. In this study, three different hydroxyapatite (HA) to beta tricalcium phosphate (β-TCP) ratios of biphasic calcium phosphate (BCP) scaffolds, BCP20, BCP50, and BCP80, with a mean pore size of 300μm and 65% porosity were prepared from phosphoric acid (H2PO4) and calcium carbonate (CaCO3) sintered at 1000°C for 2h. The extracts of these scaffolds were assessed with regard to cell viability and differentiation of odontoblasts. The high alkalinity, more calcium, and phosphate ions released that were exhibited by BCP20 decreased the viability of human dental pulp cells (HDPCs) as compared to BCP50 and BCP80. However, the cells cultured with BCP20 extract expressed high alkaline phosphatase activity and high expression level of bone sialoprotein (BSP), dental matrix protein-1 (DMP-1), and dentin sialophosphoprotein (DSPP) genes as compared to that cultured with BCP50 and BCP80 extracts. The results highlighted the effect of different scaffold ratios on the cell microenvironment and demonstrated that BCP20 scaffold can support HDPC differentiation for dentin tissue regeneration.

Screening of Transforming Growth Factor Beta 3 and Jagged2 Genes in the Malay Population With Nonsyndromic Cleft Lip With or Without Cleft Palate

OBJECTIVE

  To determine the prevalence of mutations in transforming growth factor beta 3 (TGFβ3) and Jagged2 genes and their association with nonsyndromic cleft lip with or without cleft palate (CL±P) patients.

DESIGN

  Cross-sectional study on nonsyndromic CL±P and noncleft patients.

SETTING

  Reconstructive clinic and outpatient dental clinic, Hospital Universiti Sains, Malaysia.

PATIENTS

  Blood samples of 96 nonsyndromic CL±P and 96 noncleft subjects.

MAIN OUTCOME MEASURE

  Prevalence and association of mutations in TGFβ3 and Jagged2 genes with nonsyndromic CL±P.

RESULTS

  Most of the nonsyndromic CL±P patients (53.1%) had left unilateral CLP. There were slightly more females (56.6%) compared with males. The prevalence of the mutations in the TGFβ3 gene was 17.7 (95% confidence interval [CI]: 9.5, 24.5) and in the Jagged2 gene was 12.5% (95% CI: 5.5, 18.5), which was higher compared with the noncleft group. For the TGFβ3 gene, there was no mutation in the coding region in either of the groups. All variants were single nucleotide polymorphisms located within the intronic flanking region. Two variants were identified (g.15812T>G and g.15966A>G) in both nonsyndromic CL±P and noncleft patients. However, the association was not significant (P > .05). Three variants (g.19779C>T, g.19547G>A, and g.19712C>T) were identified in the Jagged2 gene among nonsyndromic CL±P and noncleft patients. Only g.19712C>T showed a significant association with nonsyndromic CL±P patients (P = .039).

CONCLUSION

  g.19712C>T might play a crucial role in the development of cleft lip and palate. To the best of our knowledge, this is the first report of the mutation found within intron 13 of the Jagged2 gene among nonsyndromic CL±P Malay patients.

Proliferation rate of stem cells derived from human dental pulp and identification of differentially expressed genes

Stem cells from human exfoliated deciduous teeth (SHED) and dental pulp stem cells (DPSCs) obtained from the dental pulp of human extracted tooth were cultured and characterized to confirm that these were mesenchymal stem cells. The proliferation rate was assessed using AlamarBlue® cell assay. The differentially expressed genes in SHED and DPSCs were identified using the GeneFishing™ technique. The proliferation rate of SHED (P < 0.05) was significantly higher than DPSCs while SHED had a lower multiplication rate and shorter population doubling time (0.01429, 60.57 h) than DPSCs (0.00286, 472.43 h). Two bands were highly expressed in SHED and three bands in DPSCs. Sequencing analysis showed these to be TIMP metallopeptidase inhibitor 1 (TIMP1), and ribosomal protein s8, (RPS8) in SHED and collagen, type I, alpha 1, (COL1A1), follistatin-like 1 (FSTL1), lectin, galactoside-binding, soluble, 1, (LGALS1) in DPSCs. TIMP1 is involved in degradation of the extracellular matrix, cell proliferation and anti-apoptotic function and RPS8 is involved as a rate-limiting factor in translational regulation; COL1A1 is involved in the resistance and elasticity of the tissues; FSTL1 is an autoantigen associated with rheumatoid arthritis; LGALS1 is involved in cell growth, differentiation, adhesion, RNA processing, apoptosis and malignant transformation. This, along with further protein expression analysis, holds promise in tissue engineering and regenerative medicine.

In vitro cytotoxic evaluation of processed natural coral in human osteoblasts

This study aimed to evaluate the in vitro cytotoxic effects of locally produced processed natural coral (PNC) using human osteoblasts (HOS). Cytotoxicity was not observed when HOS cells were cultured with PNC, as assessed by (3-(4,5-dimethylthiazol-2-yl)-2-5-diphenyl tetrazolium bromide; MTT) and Neutral Red (NR) assays at concentration up 200 mg/mL for up to 72 hours. Flow cytometry (FCM) analysis showed that PNC (200 mg/mL) did not decrease viability of HOS cells after 48 and 72 hours of treatment. In a cell attachment study, the HOS cells attached to the edge of the PNC disc, and later grew into the pores of the PNC disc. All results from these studies indicate that locally produced PNC material is noncytotoxic and favors the growth of HOS cells.

Microsatellite instability and loss of heterozygosity in oral squamous cell carcinoma in Malaysian population

Loss of heterozygosity (LOH) and microsatellite instability (MSI) have been documented as important events in oral squamous cell carcinoma (OSCC). Five microsatellite markers D3S192, D3S966, D3S647, D3S1228 and D3S659 were selected on chromosome 3p because of high frequency of alterations reported in head and neck squamous cell carcinoma and the involvement of von Hippel Lindau (VHL) at 3p25-26 and the fragile histidine triad (FHIT) at 3p14.2 genes proven in many tumour types. A total of 50 archival tissue samples of OSCC and corresponding normal samples were analyzed for LOH and MSI status. The overall LOH for the markers selected on 3p was 56 out of 189 informative cases (29.6%). The most frequent LOH was identified for the marker D3S966 which was 18/42 (42.8%) of informative cases suggesting the presence of putative tumour suppressor genes (TSGs) in this loci. In this study, high frequency of microsatellite instability was found in D3S966 which was 28.6% of informative cases; this reveals the possibility of mutations of MMR genes in this region. Frequent microsatellite alterations (MA) were observed in 3 markers D3S966 (71.4%), D3S1228 (56.7%) and D3S192 (41.0%). There was no significant association between LOH with gender, tumour stages and differentiation grades. However, there was a significant association between tumour stage and differentiation grades with MSI status in OSCC in Malaysian population with p values of 0.002 and 0.035, respectively. There was also a significant association between MA and differentiation grades (p=0.041).

Clinical manifestations in trisomy 9

Complete trisomy 9 is a lethal diagnosis and most fetuses diagnosed thus die prenatally or during the early postnatal period and majority of such cases have been known to end in spontaneous abortion in the first trimester itself. One such rare survival of fetus ending in normal delivery and surviving until 20 days is reported here detailing the clinical manifestations of the child during the period of survival. The salient clinical features observed were small face, wide fontanel, prominent occiput, micrognathia, low set ears, upslanting palpebral fissures, high arched palate, short sternum, overlapping fingers, limited hip abduction, rocker bottom feet, heart murmurs and also webbed neck, characteristic of this trisomy 9 syndrome.

Cytogenetics: past, present and future

Fifty years have elapsed since the discovery of the number of human chromosomes in 1956. Newer techniques have been developed since then, ranging from the initial conventional banding techniques to the currently used molecular array comparative genomic hybridisation. With a combination of these conventional and molecular techniques, cytogenetics has become an indispensable tool for the diagnosis of various genetic disorders, paving the way for possible treatment and management. This paper traces the history and evolution of cytogenetics leading up to the current state of technology.

Detection of beta-globin gene mutations among Kelantan Malay thalassaemia patients by polymerase chain reaction restriction fragment length polymorphism

INTRODUCTION

Beta-thalassaemia major is an autosomal recessive disorder that results in severe microcytic, hypochromic, haemolytic anaemia among affected patients. Beta-thalassaemia has emerged as one of the most common public health problems in Malaysia, particularly among Malaysian Chinese and Malays. This study aimed to observe the spectrum of mutations found in Kelantan Malay beta-thalassaemia major patients who attended the Paediatrics Daycare Unit, Hospital Universiti Sains Malaysia, Kelantan, Malaysia, the data of which was being used in establishing the prenatal diagnosis in this Human Genome Centre.

METHODS

This was a cross-sectional study conducted with 35 Kelantan Malay beta-thalassaemia major patients. DNA was extracted from the blood collected from the patients and subjected to polymerase chain reaction (PCR) amplification. Six restriction enzymes were used to digest the PCR products for the detection of mutations.

RESULTS

Five out of the six beta-globin gene defects were detected, namely, IVS-1 nt5 (G>C), IVS-1 nt1 (G>T), codon 26 (G>A), codon 41-42 (4 bp del) and codon 19 (A>G). The mutation which was not observed in this study was in codon 15 (G>A). The two most common mutations observed were codon 26 (G>A) and IVS-1 nt5 (G>C), which was detected in 26 and 17 patients, respectively. Two patients did not show any of the six mutations.

CONCLUSION

Our results added to the existing data on the common beta-globin gene defects in Kelantan Malay beta-thalassaemia patients.

Gene expression analysis of osteoblasts seeded in coral scaffold

Coral matrix of Porites sp. has the suitable properties for bone cell growth. This study was aimed to study the gene expression levels of osteoblast specific genetic markers; RUNX2, osteopontin, alkaline phosphatase and osteocalcin from osteoblasts seeded in coral scaffold, which are important in determining the feasibility of osteoblasts. Human osteoblasts were inoculated onto the processed coral in Dulbecco's Minimum Essential Medium. The cells were trypsinized on day 1, 7, 14, 18, and 21 and added with RNALater for preservation of RNA in cells. The RNA was extracted using commercial RNA extraction kit and the respective genes were amplified using RT-PCR kit and analyzed qualitatively on 1.5% agarose gel. The expressions were evaluated with the Integrated Density Value based on the intensity of band for different periods of cell harvest. Increased expressions of the RUNX2, osteopontin, alkaline phosphatase and osteocalcin genes in the present study proved that coral is a favorable carrier for osteogenetically competent cells to attach and remain viable.

Turner syndrome diagnosed in northeastern Malaysia

INTRODUCTION

Turner syndrome affects about one in 2,000 live-born females, and the wide range of somatic features indicates that a number of different X-located genes are responsible for the complete phenotype. This retrospective study highlights the Turner syndrome cases confirmed through cytogenetic analysis at the Human Genome Centre of Universiti Sains Malaysia, from 2001 to 2006.

METHODS

Lymphocyte cultures were set up using peripheral blood samples, chromosomes were prepared, G-banded, karyotyped and analysed in accordance to guidelines from the International System for Human Cytogenetic Nomenclature.

RESULTS

The various karyotype patterns observed were 45,X; 46,X,i, (Xq); 45,X/45,X,+mar; 45,X/46,X,i,(Xq) and 45,X/46,XY. The mean age of our patients with Turner syndrome was 21 years, and the most common clinical features encountered in all these patients were short stature (100 percent), primary amenorrhoea (85.7 percent), absence of secondary sexual characteristics (57.1 percent), scanty pubic and axillary hair (50 percent), webbed neck (42.9 percent), wide carrying angle (42.9 percent), rudimentary uterus with bilateral streak ovaries (42.9 percent), underdeveloped breasts (35.7 percent) and wide-spaced nipples (21.4 percent).

CONCLUSION

Even though there is no causal therapy for Turner syndrome, management and treatment are possible for malformations and conditions associated with it. In addition, counselling of the parents and of the patients themselves are necessary. Hence, establishing an early diagnosis, educating and increasing awareness among doctors, and if possible, a prenatal diagnosis, will help in early intervention, genetic counselling and in improving the quality of life in these patients.

In vitro genotoxicity tests for polyhydroxybutyrate – A synthetic biomaterial

The aims of this study are to determine the mutagenicity of a locally produced polyhydroxybutyrate (PHB) using Salmonella mutagenicity test and to find out if PHB altered the expression of p53 and c-myc proto-oncogenes and bcl-xl and bcl-xs anti-apoptotic genes in the human fibroblast cell line, MRC-5. Different concentrations of PHB were incubated with special genotypic variants of Salmonella strains (TA1535, TA1537, TA1538, TA98 and TA100) carrying mutations in several genes both with and without metabolic activation (S9) and the test was assessed based on the number of revertant colonies. The average number of revertant colonies per plate treated with PHB was less than double as compared to that of negative control. For the gene expression analyses, fibroblast cell lines were treated with PHB at different concentrations and incubated for 1, 12, 24 and 48 h separately. The total RNA was isolated and analysed for the expression of p53, c-myc, bcl-xl and bcl-xs genes. The PHB did not show over or under expression of the genes studied. The above tests indicate that the locally produced PHB is non-genotoxic and does not alter the expression of the proto-oncogenes and anti-apoptotic genes considered in this study.

Cytogenetic and clinical profile of Down syndrome in Northeast Malaysia

INTRODUCTION

This study was designed to evaluate the karyotype pattern, clinical features and other systemic anomalies of patients with Down syndrome in Malaysia.

METHODS

Retrospective analysis was performed on the case records of 149 patients confirmed as Down syndrome by cytogenetic analysis at Human Genome Centre and Genetic Clinic at the Universiti Sains Malaysia.

RESULTS

Among the 149 cases of Down syndrome presenting over a period of 4.2 years, free trisomy (non-disjunction) was present in 141 cases (94.6 percent). One case (0.7 percent) had translocation, and seven cases (4.7 percent) were mosaics. Average age at presentation was 10.6 months. Average maternal age at birth of the affected child was 32.3 years. The prominent craniofacial features noted were upslanting palpebral fissures (89.3 percent), flat facial profile (64.9 percent), low set ears (56.1 percent), epicanthic folds (17.5 percent) and protruding tongue (19.2 percent). A total of 52.6 percent of the cases had documented hypotonia. Characteristic limb and dermatoglyphic anomalies included short stubby fingers (24.5 percent), sandal gap (33.3 percent), unilateral or bilateral simian crease (36.8 percent) and clinodactyly (19.2 percent). Ophthalmological abnormalities, such as hypertelorism, were presented in 33.3 percent of the cases. Congenital heart disease was diagnosed in 35 out of 71 cases (49.3 percent) and gastrointestinal anomalies were noted in 18 out of 79 cases (22.7 percent) analysed.

CONCLUSION

Efforts to establish early diagnosis and a proper screening for high association with systemic anomalies should be undertaken among the Down syndrome patients in this population.

Chromosome aberration test for hydroxyapatite in sheep

The present study is aimed at finding the mutagenicity and cytotoxicity of dense form of synthetic hydroxyapatite (Source: School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia) in the blood of sheep. The biomaterial was implanted in the tibia of Malin, an indigenous sheep breed of Malaysia. Blood was collected from the sheep before implantation of the biomaterial, cultured and a karyological study was made. Six weeks after implantation, blood was collected from the same animal, cultured and screened for chromosome aberrations. The mitotic indices and karyological analysis indicated that the implantation of synthetic hydroxyapatite (dense form) did not produce any cytotoxicity or chromosome aberrations in the blood of sheep.

In vivo chromosome aberration test for hydroxyapetite in mice

This study evaluates the cytotoxic and mutagenic effect of synthetic hydroxyapatite granules (source: School of Material and Mineral Resources Engineering, Universiti Sains Malaysia) in the bone marrow cells of mice. Mice are exposed to synthetic hydroxyapatite granules, the bone marrow cells are collected and observed for chromosome aberrations. No chromosome aberrations were noticed in the animals exposed to distilled water (negative control) and to the test substance, synthetic hydroxyapatite granules (treatment) groups. Chromosome aberrations were observed in the animals exposed to Mitomycin C (positive control group). There was no indication of cytotoxicity due to synthetic hydroxyapatite granules in the animals as revealed by the mitotic index. Hence, synthetic hydroxyapatite granules are considered non-mutagenic under the prevailing test conditions.