Displaying publications 1 - 20 of 35 in total

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  1. Manan NM, Musa S, Nor MMD, Saari CZ, Al-Namankany A
    Int J Paediatr Dent, 2024 May;34(3):267-276.
    PMID: 37985445 DOI: 10.1111/ipd.13132
    BACKGROUND: The Abeer Children Dental Anxiety Scale (ACDAS) source language was developed and validated in an English-speaking country in the UK to measure dental anxiety among children. The ACDAS also included the child's cognitive assessment, as well as feedback from the parent or the legal guardian and a dental health professional (DHP). This is the first study to validate the application of the ACDAS in Malay or Bahasa Melayu for children aged 6-16 years.

    AIM: To assess the Malay-translated version of the ACDAS, postadaptation into the local context and validation by the content and construct experts.

    DESIGN: The English ACDAS was translated into Malay first through forward translation and then through backward translation. The prefinal translated version of the instrument was designed, with the participation of 61 children and 61 parents or legal guardians. Subsequently, a final cross-cultural adaptation of the instrument was then made for another group of participants and evaluated for validity and test-retest reliability among 144 children and 144 parents or legal guardians participating in the self-report feedback process at the Paediatric Dental Clinic, Faculty of Dentistry, Universiti Malaya, Kuala Lumpur, Malaysia. The cross-cultural adaptation of the instrument considered translating to Malaysian national language and adapting to its culture.

    RESULTS: The Malay-translated ACDAS consisted of 19 items. The translated version of Malaysian-ACDAS (MY-ACDAS) achieved an acceptable agreement between six expert committee members with an internal consistency (Cronbach's alpha value, αconsistency) of 0.839. The test-retest reliability results of all participants support semantic and conceptual equivalence as an accepted construct validity between the children, parents and DHPs across the multicultural Malaysian population.

    CONCLUSION: The MY-ACDAS is a valid and reliable scale for measuring dental anxiety among Malaysian children.

  2. Lim SP, Zainal Aalam N, Chik Z, Musa S
    Eur Arch Paediatr Dent, 2023 Dec;24(6):737-749.
    PMID: 37923916 DOI: 10.1007/s40368-023-00837-8
    PURPOSE: Silver diamine fluoride (SDF) is a medication used for the arrestment of dental caries. This study aims to determine the pharmacokinetics (PK) of silver and fluoride following SDF application in healthy children with dental caries.

    METHODS: A total of 15 subjects, aged 4 to 10 years, with at least one cavity on a primary tooth, were recruited for this study. Urine samples were collected at baseline, first 24 h (F1) and second 24 h (F2) after SDF treatment for analysis of silver and fluoride content. Hair samples were also collected at baseline and at 7, 14, 30, 60, 75, and 90 days after SDF treatment to analyze silver content.

    RESULTS: Participants with under or over-collection of urine, or failure to provide urine collection were excluded for fluoride analysis. As a result, eight subjects' urine samples were eligible for fluoride analysis. Significant correlations were observed between baseline urinary fluoride levels and F1/F2 levels. Pairwise comparisons from Friedman's test showed significant differences between baseline and F1 fluoride levels. For silver analysis, 15 subjects were studied. F1 urinary silver levels were higher than baseline and F2 levels. Subsequent to SDF treatment, hair silver levels displayed fluctuations around the baseline. None of the participants reported adverse effects, and all caries teeth ceased progression within 30 days.

    CONCLUSIONS: The urinary fluoride levels after SDF treatment, although higher, were not clinically significant. Urinary and hair silver levels were negligible. Therefore, SDF appears safe to be used among children.

  3. Ibrahim NA, Nor NAM, Azizi NZ, Hamzah TNNT, Dziaruddin N, Musa S
    J Clin Pediatr Dent, 2023 Jul;47(4):46-53.
    PMID: 37408346 DOI: 10.22514/jocpd.2023.034
    Many children are affected by early childhood caries (ECC) with some requiring dental treatment under general anesthesia (GA). In pediatric dentistry, GA is one of the established methods of behavior management. GA data is useful for understanding the caries burden among young children. This study aimed to determine the trends, patient characteristics, and types of treatments conducted under GA among young children in a Malaysian dental hospital over a 7-year period. A retrospective study using pediatric patient records from 2013 to 2019 was conducted on children aged 2-6 years (24-71 months) having ECC. Relevant data were collected and analyzed. In total, 381 children with a mean age of 49.8 months were identified. Some of the ECC cases were associated with abscesses (32.5%) and multiple retained roots (36.7%). Over a 7-year period, there was an upward trend of preschool children receiving GA. Of the 4713 carious teeth treated, 55.1% were extracted, 29.9% were restored, 14.3% had preventive procedures, and 0.4% were pulp treated. Mean extractions were significantly higher among preschoolers compared to toddlers (p = 0.001), while preventive treatment was markedly higher among toddlers. In terms of the type of restorative materials, almost similar distribution was observed between the two age groups with 86.5% treated using composite restorations. Dental treatment under GA was more frequently used among preschoolers than in toddlers, with extractions and restoration with composite resin being the common treatment options. The findings can help decision-makers or relevant parties address the burden of ECC and enhance oral health promotion activities.
  4. Althomali YM, Musa S, Manan NM, Nor NAM
    Pediatr Dent, 2022 Jul 15;44(4):249-254.
    PMID: 35999682
    Purpose: The purpose of this study was to evaluate the clinical retention capabilities of a self-etch adhesive system (experimental group) and conventional acid-etch (control group) techniques and compare the caries incidence within six months and 24 months of follow-up periods. Methods: A total of 47 healthy children with a mean age of 9.7 years and either sound or noncavitated erupted permanent first molars were included in the trial. A total of 188 molars were randomly assigned in a split-mouth design for the self-etch mode in the universal adhesive or conventional acid-etch. Differences in sealant retention and caries incidence were compared at six and 24 months after sealant placement using a chi-square test. Results: Within 24 months of follow-up, the retention of fissure sealant applied using conventional acid etching (41 out of 66; 62.1 percent) was significantly higher (P<0.05) than that of the fissure sealant applied using self-etching mode in the universal adhesive system (17 out of 66; 25.8 percent). There was no significant difference in caries incidence between the two groups up to 24 months after sealant placement. Conclusion: With 24 months of follow-up, the retention of the conventional acid-etching technique were superior to those of the self-etch technique.
  5. Lau MN, Kunasekaran W, On YY, Tan LJ, Zaharin NA, H A Ghani S, et al.
    PLoS One, 2022;17(12):e0279129.
    PMID: 36574419 DOI: 10.1371/journal.pone.0279129
    The objective of this study was to compare the characteristics of Dental Pulp Stem Cells (DPSCs) derived from healthy human permanent teeth with those that were orthodontically-intruded to serve as potential Mesenchymal Stem Cells (MSC). Recruited subjects were treated with orthodontic intrusion on one side of the maxillary first premolar while the opposite side served as the control for a period of six weeks before the dental pulp was extracted. Isolated DPSCs from both the control and intruded samples were analyzed, looking at the morphology, growth kinetics, cell surface marker profile, and multilineage differentiation for MSC characterisation. Our study showed that cells isolated from both groups were able to attach to the cell culture flask, exhibited fibroblast-like morphology under light microscopy, able to differentiate into osteogenic, adipogenic and chondrogenic lineages as well as tested positive for MSCs cell surface markers CD90 and CD105 but negative for haematopoietic cell surface markers CD34 and HLA-DR. Both groups displayed a trend of gradually increasing population doubling time from passage 1 to passage 5. Viable DPSCs from both groups were successfully recovered from their cryopreserved state. In conclusion, DPSCs in the dental pulp of upper premolar not only remained viable after 6 weeks of orthodontic intrusion using fixed appliances but also able to develop into MSCs.
  6. Elnaim ALK, Musa S, Wong MP, Sagap I
    Malays J Med Sci, 2021 Oct;28(5):102-107.
    PMID: 35115892 DOI: 10.21315/mjms2021.28.5.10
    Objective: This study was designed as a prospective and interventional study that evaluated LigaSure™ haemorrhoidectomies with regional anaesthesia as a daycare procedure.

    Methods: Patients with third- and fourth-degree haemorrhoids were recruited from the clinic from January 2018 to December 2019. The procedure was performed as a day case under regional anaesthesia. Using a LigaSureTM device, excisional haemorrhoidectomies (Milligan-Morgan haemorrhoidectomy) were performed without sutures or an anal sponge. We evaluated wound bleeding, pain and urinary retention per daycare protocols.

    Results: A total of 264 patients were enrolled. There were 153 males (57.9%) with a median age of 30 years old (range 16 years old-80 years old). A total of 142 patients (54%) had third-degree haemorrhoids, while the rest had fourth-degree haemorrhoids. The median operating time was 8 min (range 4 min-17 min) and minimal blood loss was observed. During follow-up, the complications were one case (0.3%) had anal stenosis, one case (0.3%) had minimal bleeding and one case (0.3%) had urine retention. Upon discharge, four patients (1.5%) required additional analgesia and another four (1.5%) developed post-spinal headaches. No incontinence was encountered.

    Conclusion: LigaSure™ excisional haemorrhoidectomy is a safe and effective daycare procedure with acceptable re-admission and complication rates.

  7. Sidi Omar SFN, Ngui R, Ab Rahman SZ, Foo JC, Wang QY, Hassan NA, et al.
    Trop Biomed, 2021 Sep 01;38(3):276-282.
    PMID: 34362870 DOI: 10.47665/tb.38.3.068
    This study sought to determine the prevalence of pathogenic and non-pathogenic bacteria in the oral cavities of children with cancer. There were 68 paediatric patients with cancer who were included in this study. Oral swab samples from the dorsum of tongues and mouth floors of these patients were subjected to culture, staining, and molecular methods to detect the bacteria. The overall prevalence of gram-positive and gram-negative bacteria was 79.4% (54/68; 95% CI = 68.4 - 87.3) and 25% (17/68; 95% CI = 16.2 - 36.4), respectively. Streptococcus salivarius and Streptococcus parasanguinis were the predominant pathogenic grampositive bacteria, while Neisseria subflava and Neisseria perflava were the most common pathogenic gram-negative bacteria. The results revealed that the number of bacteria isolates recovered in patients receiving cancer treatment was higher (55.9%) than those who had not received treatment (16.2%). Therefore, more isolated pathogenic bacteria were observed post-therapy (54.4%). Pathogenic organisms can have significant implications on patient health. Awareness of the types of bacteria inhabiting the oral cavity is essential to predict and prevent dental problems, and their associated systemic complications. Findings on the diversity of oral microflora can also provide a better understanding of the aetiology of oral diseases in paediatric patients receiving cancer treatment.
  8. Schepaschenko D, Chave J, Phillips OL, Lewis SL, Davies SJ, Réjou-Méchain M, et al.
    Sci Data, 2019 10 10;6(1):198.
    PMID: 31601817 DOI: 10.1038/s41597-019-0196-1
    Forest biomass is an essential indicator for monitoring the Earth's ecosystems and climate. It is a critical input to greenhouse gas accounting, estimation of carbon losses and forest degradation, assessment of renewable energy potential, and for developing climate change mitigation policies such as REDD+, among others. Wall-to-wall mapping of aboveground biomass (AGB) is now possible with satellite remote sensing (RS). However, RS methods require extant, up-to-date, reliable, representative and comparable in situ data for calibration and validation. Here, we present the Forest Observation System (FOS) initiative, an international cooperation to establish and maintain a global in situ forest biomass database. AGB and canopy height estimates with their associated uncertainties are derived at a 0.25 ha scale from field measurements made in permanent research plots across the world's forests. All plot estimates are geolocated and have a size that allows for direct comparison with many RS measurements. The FOS offers the potential to improve the accuracy of RS-based biomass products while developing new synergies between the RS and ground-based ecosystem research communities.
  9. Gnanasegaran N, Govindasamy V, Kathirvaloo P, Musa S, Abu Kasim NH
    J Tissue Eng Regen Med, 2018 02;12(2):e881-e893.
    PMID: 28079995 DOI: 10.1002/term.2401
    Parkinson's disease (PD) is characterized by tremors and cognitive issues, and is due to the death of dopaminergic (DA-ergic) neurons in brain circuits that are responsible for producing neurotransmitter dopamine (DA). Currently, cell replacement therapies are underway to improve upon existing therapeutic approaches such as drug treatments and electrical stimulation. Among the widely available sources, dental pulp stem cells (DPSCs) from deciduous teeth have gained popularity because of their neural crest origin and inherent propensity toward neuronal lineage. Despite the various pre-clinical studies conducted, an important factor yet to be elucidated is the influence of growth phases in a typical trans-differentiation process. This study selected DPSCs at three distinct time points with variable growth phase proportions (G0/G1, S and G2/M) for in vitro trans-differentiation into DA-ergic-like cells. Using commercially available PCR arrays, we identified distinct gene profiles pertaining to cell cycles in these phases. The differentiation outcomes were assessed in terms of morphology and gene and protein expression, as well as with functional assays. It was noted that DPSCs with the highest G0/G1 phase were comparatively the best, representing at least a 2-fold up regulation (p 
  10. Gnanasegaran N, Govindasamy V, Simon C, Gan QF, Vincent-Chong VK, Mani V, et al.
    Eur J Clin Invest, 2017 Mar 30.
    PMID: 28369799 DOI: 10.1111/eci.12753
    BACKGROUND: Parkinson's disease (PD) is a neurodegenerative disease caused by the loss of dopaminergic (DA-ergic) neurons in the substantia nigra (SN) and represented as a huge threat to the geriatric population. Cell replacement therapies (CRTs) have been proposed as a promising strategy to slow down or replace neuronal loss. Among the widely available cell sources, dental pulp stem cells (DPSCs) portray as an attractive source primarily due to their neural crest origin, ease of tissue procurement and less ethical hurdles.

    MATERIALS AND METHODS: We first demonstrated the in vitro differentiation ability of DPSCs towards DA-ergic-like cells before evaluating their neuro-protection/neuro-restoration capacities in MPTP-induced mice. Transplantation via intrathecal was performed with behavioural assessments being evaluated every fortnight. Subsequent analysis investigating their immuno-modulatory behaviour was conducted using neuronal and microglial cell lines.

    RESULTS: It was apparent that the behavioural parameters began to improve corresponding to tyrosine hydroxylase (TH), dopamine transporter (DAT) and dopamine decarboxylase (AADC) immunostaining in SN and striatum as early as 8-week post-transplantation (P < 0·05). About 60% restoration of DA-ergic neurons was observed at SN in MPTP-treated mice after 12-week post-transplantation. Similarly, their ability to reduce toxic effects of MPTP (DNA damages, reactive oxygen species and nitric oxide release) and regulate cytokine levels was distinctly noted (P < 0·05) upon exposure in in vitro model.

    CONCLUSIONS: Our results suggest that DPSCs may provide a therapeutic benefit in the old-aged PD mice model and may be explored in stem cell-based CRTs especially in geriatric population as an attempt towards 'personalized medicine'.

  11. Ting SY, Ishola OA, Ahmed MA, Tabana YM, Dahham S, Agha MT, et al.
    J Mycol Med, 2017 Mar;27(1):98-108.
    PMID: 28041812 DOI: 10.1016/j.mycmed.2016.12.002
    The virulence of Candida albicans is dependent upon fitness attributes as well as virulence factors. These attributes include robust stress responses and metabolic flexibility. The assimilation of carbon sources is important for growth and essential for the establishment of infections by C. albicans. Previous studies showed that the C. albicans ICL1 genes, which encode the glyoxylate cycle enzymes isocitratelyase are required for growth on non-fermentable carbon sources such as lactate and oleic acid and were repressed by 2% glucose. In contrast to S. cerevsiae, the enzyme CaIcl1 was not destabilised by glucose, resulting with its metabolite remaining at high levels. Further glucose addition has caused CaIcl1 to lose its signal and mechanisms that trigger destabilization in response to glucose. Another purpose of this study was to test the stability of the Icl1 enzyme in response to the dietary sugars, fructose, and galactose. In the present study, the ICL1 mRNAs expression was quantified using Quantitative Real Time PCR, whereby the stability of protein was measured and quantified using Western blot and phosphoimager, and the replacing and cloning of ICL1 ORF by gene recombination and ubiquitin binding was conducted via co-immuno-precipitation. Following an analogous experimental approach, the analysis was repeated using S. cerevisiaeas a control. Both galactose and fructose were found to trigger the degradation of the ICL1 transcript in C. albicans. The Icl1 enzyme was stable following galactose addition but was degraded in response to fructose. C. albicans Icl1 (CaIcl1) was also subjected to fructose-accelerated degradation when expressed in S. cerevisiae, indicating that, although it lacks a ubiquitination site, CaIcl1 is sensitive to fructose-accelerated protein degradation. The addition of an ubiquitination site to CaIcl1 resulted in this enzyme becoming sensitive to galactose-accelerated degradation and increases its rate of degradation in the presence of fructose. It can be concluded that ubiquitin-independent pathways of fructose-accelerated enzyme degradation exist in C. albicans.
  12. Musa, S., Radzi, M.A.M.
    MyJurnal
    This research presents compensation of current harmonic disturbance in power system network using
    shunt active power filter. In this paper, harmonic extraction using Synchronous Reference Frame
    Fundamental technique (SRFF) was investigated for three phase 3-wire system. It proposes a method
    based on direct current measurement of load currents using a band pass filter at low cut off frequencies
    to improve the filtering ability in highly contaminated loads. The proposed filter consists of second
    order low pass and high pass filters cascaded together at suitable frequencies, estimated based on the
    output of these units to mitigate the current harmonics. The performance of the system was simulated
    in Matlab Platform and evaluated considering total harmonic distortion of the source current in a threephase
    balanced network. The simulation results show the ability of the proposed tracking scheme to
    accurately estimate harmonics.
  13. Rafieerad AR, Bushroa AR, Nasiri-Tabrizi B, Fallahpour A, Vadivelu J, Musa SN, et al.
    J Mech Behav Biomed Mater, 2016 08;61:182-196.
    PMID: 26874249 DOI: 10.1016/j.jmbbm.2016.01.028
    PVD process as a thin film coating method is highly applicable for both metallic and ceramic materials, which is faced with the necessity of choosing the correct parameters to achieve optimal results. In the present study, a GEP-based model for the first time was proposed as a safe and accurate method to predict the adhesion strength and hardness of the Nb PVD coated aimed at growing the mixed oxide nanotubular arrays on Ti67. Here, the training and testing analysis were executed for both adhesion strength and hardness. The optimum parameter combination for the scratch adhesion strength and micro hardness was determined by the maximum mean S/N ratio, which was 350W, 20 sccm, and a DC bias of 90V. Results showed that the values calculated in the training and testing in GEP model were very close to the actual experiments designed by Taguchi. The as-sputtered Nb coating with highest adhesion strength and microhardness was electrochemically anodized at 20V for 4h. From the FESEM images and EDS results of the annealed sample, a thick layer of bone-like apatite was formed on the sample surface after soaking in SBF for 10 days, which can be connected to the development of a highly ordered nanotube arrays. This novel approach provides an outline for the future design of nanostructured coatings for a wide range of applications.
  14. Vasanthan P, Jayaraman P, Kunasekaran W, Lawrence A, Gnanasegaran N, Govindasamy V, et al.
    Naturwissenschaften, 2016 Aug;103(7-8):62.
    PMID: 27379400 DOI: 10.1007/s00114-016-1387-7
    Human deciduous periodontal ligament stem cells have been introduced for as an easily accessible source of stem cells from dental origin. Although recent studies have revealed the ability of these stem cells in multipotential attribute, their efficiency of hepatic lineage differentiation has not been addressed so far. The aim of this study is to investigate hepatic lineage fate competence of periodontal ligament stem cells through direct media induction. Differentiation of periodontal ligament stem cells into hepatocyte-like cells was conducted by the exposure of two phase media induction. First phase was performed in the presence of hepatocyte growth factors to induce a definitive endoderm formation. In the subsequent phase, the cells were treated with oncostatin M and dexamethosone followed by insulin and transferrin to generate hepatocyte-like cells. Hepatic-related characters of the generated hepatocyte-like cells were determined at both mRNA and protein level followed by functional assays. Foremost changes observed in the generation of hepatocyte-like cells were the morphological features in which these cells were transformed from fibroblastic shape to polygonal shape. Temporal expression of hepatic markers ranging from early endodermal up to late markers were detected in the hepatocyte-like cells. Crucial hepatic markers such as glycogen storage, albumin, and urea secretion were also shown. These findings exhibited the ability of periodontal ligament stem cells of dental origin to be directed into hepatic lineage fate. These cells can be regarded as an alternative autologous source in the usage of stem cell-based treatment for liver diseases.
  15. Abd Rahman F, Mohd Ali J, Abdullah M, Abu Kasim NH, Musa S
    J. Periodontol., 2016 07;87(7):837-47.
    PMID: 26846966 DOI: 10.1902/jop.2016.150610
    BACKGROUND: This study investigates the effects of aspirin (ASA) on the proliferative capacity, osteogenic potential, and expression of growth factor-associated genes in periodontal ligament stem cells (PDLSCs).

    METHODS: Mesenchymal stem cells (MSCs) from PDL tissue were isolated from human premolars (n = 3). The MSCs' identity was confirmed by immunophenotyping and trilineage differentiation assays. Cell proliferation activity was assessed through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Polymerase chain reaction array was used to profile the expression of 84 growth factor-associated genes. Pathway analysis was used to identify the biologic functions and canonic pathways activated by ASA treatment. The osteogenic potential was evaluated through mineralization assay.

    RESULTS: ASA at 1,000 μM enhances osteogenic potential of PDLSCs. Using a fold change (FC) of 2.0 as a threshold value, the gene expression analyses indicated that 19 genes were differentially expressed, which includes 12 upregulated and seven downregulated genes. Fibroblast growth factor 9 (FGF9), vascular endothelial growth factor A (VEGFA), interleukin-2, bone morphogenetic protein-10, VEGFC, and 2 (FGF2) were markedly upregulated (FC range, 6 to 15), whereas pleotropin, FGF5, brain-derived neurotrophic factor, and Dickkopf WNT signaling pathway inhibitor 1 were markedly downregulated (FC 32). Of the 84 growth factor-associated genes screened, 35 showed high cycle threshold values (≥35).

    CONCLUSIONS: ASA modulates the expression of growth factor-associated genes and enhances osteogenic potential in PDLSCs. ASA upregulated the expression of genes that could activate biologic functions and canonic pathways related to cell proliferation, human embryonic stem cell pluripotency, tissue regeneration, and differentiation. These findings suggest that ASA enhances PDLSC function and may be useful in regenerative dentistry applications, particularly in the areas of periodontal health and regeneration.

  16. Gnanasegaran N, Govindasamy V, Musa S, Abu Kasim NH
    Cytotechnology, 2016 Mar;68(2):343-53.
    PMID: 25322895 DOI: 10.1007/s10616-014-9787-z
    Among the debilitating diseases, neurological related diseases are the most challenging ones to be treated using cell replacement therapies. Recently, dental pulp stem cells (SHED) were found to be most suitable cell choice for neurological related diseases as evidenced with many preclinical studies. To enhance the neurological potential of SHED, we recapitulated one of the pharmacological therapeutic tools in cell replacement treatment, we pre-conditioned dental pulp stem cells (SHED) with culture medium of ReNCell VM, an immortalized neuron progenitor cell, prior to neurogenesis induction and investigated whether this practice enhances their neurogenesis potential especially towards dopaminergic neurons. We hypothesed that the integration of pharmacological practices such as co-administration of various drugs, a wide range of doses and duration as well as pre-conditioning into cell replacement may enhance the efficacy of stem cell therapy. In particular, pre-conditioning is shown to be involved in the protective effect from some membrano-tropic drugs, thereby improving the resistance of cell structures and homing capabilities. We found that cells pre-treated with ReNCell VM conditioned medium displayed bipolar structures with extensive branches resembling putative dopaminergic neurons as compared to non-treated cells. Furthermore, many neuronal related markers such as NES, NR4A2, MSI1, and TH were highly expressed (fold changes > 2; p 
  17. Jayaraman P, Govindasamy V, Gnanasegaran N, Kunasekaran W, Vasanthan P, Musa S, et al.
    Clin Oral Investig, 2016 Jan;20(1):109-16.
    PMID: 26048030 DOI: 10.1007/s00784-015-1497-1
    Long-term culture system is used to prevent the impediment of insufficient cells and is good for low starting materials such as dental pulp or periodontal ligament. In general, although cell viability and functionality are the most common aspects taken into consideration in culturing cells for a long term, they may not truly represent the biological state of the cells. Hence, we explored the behaviour of another important aspect which is the immune properties in long-term cultured cells.
  18. Abu Kasim NH, Govindasamy V, Gnanasegaran N, Musa S, Pradeep PJ, Srijaya TC, et al.
    J Tissue Eng Regen Med, 2015 Dec;9(12):E252-66.
    PMID: 23229816 DOI: 10.1002/term.1663
    The discovery of mesenchymal stem cells (MSCs) from a myriad of tissues has triggered the initiative of establishing tailor-made stem cells for disease-specific therapy. Nevertheless, lack of understanding on the inherent differential propensities of these cells may restrict their clinical outcome. Therefore, a comprehensive study was done to compare the proliferation, differentiation, expression of cell surface markers and gene profiling of stem cells isolated from different sources, viz. bone marrow, Wharton's jelly, adipose tissue and dental pulp. We found that although all MSCs were phenotypically similar to each other, Wharton's jelly (WJ) MSCs and dental pulp stem cells (DPSCs) were highly proliferative as compared to bone marrow (BM) MSCs and adipose tissue (AD) MSCs. Moreover, indistinguishable cell surface characteristics and differentiation capacity were confirmed to be similar among all cell types. Based on gene expression profiling, we postulate that BM-MSCs constitutively expressed genes related to inflammation and immunodulation, whereas genes implicated in tissue development were highly expressed in AD-MSCs. Furthermore, the transcriptome profiling of WJ-MSCs and DPSCs revealed an inherent bias towards the neuro-ectoderm lineage. Based on our findings, we believe that there is no unique master mesenchymal stem cell that is appropriate to treat all target diseases. More precisely, MSCs from different sources exhibit distinct and unique gene expression signatures that make them competent to give rise to specific lineages rather than others. Therefore, stem cells should be subjected to rigorous characterization and utmost vigilance needs to be adopted in order to choose the best cellular source for a particular disease.
  19. Vasanthan P, Govindasamy V, Gnanasegaran N, Kunasekaran W, Musa S, Abu Kasim NH
    J Cell Mol Med, 2015 Mar;19(3):566-80.
    PMID: 25475098 DOI: 10.1111/jcmm.12381
    MicroRNAs (miRNAs) are small non-coding RNAs that regulate translation of mRNA into protein and play a crucial role for almost all biological activities. However, the identification of miRNAs from mesenchymal stem cells (MSCs), especially from dental pulp, is poorly understood. In this study, dental pulp stem cells (DPSCs) were characterized in terms of their proliferation and differentiation capacity. Furthermore, 104 known mature miRNAs were profiled by using real-time PCR. Notably, we observed 19 up-regulated miRNAs and 29 significantly down-regulated miRNAs in DPSCs in comparison with bone marrow MSCs (BM-MSCs). The 19 up-regulated miRNAs were subjected to ingenuity analysis, which were composed into 25 functional networks. We have chosen top 2 functional networks, which comprised 10 miRNA (hsa-miR-516a-3p, hsa-miR-125b-1-3p, hsa-miR-221-5p, hsa-miR-7, hsa-miR-584-5p, hsa-miR-190a, hsa-miR-106a-5p, hsa-mir-376a-5p, hsa-mir-377-5p and hsa-let-7f-2-3p). Prediction of target mRNAs and associated biological pathways regulated by each of this miRNA was carried out. We paid special attention to hsa-miR-516a-3p and hsa-miR-7-5p as these miRNAs were highly expressed upon validation with qRT-PCR analysis. We further proceeded with loss-of-function analysis with these miRNAs and we observed that hsa-miR-516a-3p knockdown induced a significant increase in the expression of WNT5A. Likewise, the knockdown of hsa-miR-7-5p increased the expression of EGFR. Nevertheless, further validation revealed the role of WNT5A as an indirect target of hsa-miR-516a-3p. These results provide new insights into the dynamic role of miRNA expression in DPSCs. In conclusion, using miRNA signatures in human as a prediction tool will enable us to elucidate the biological processes occurring in DPSCs.
  20. Yazid FB, Gnanasegaran N, Kunasekaran W, Govindasamy V, Musa S
    Clin Oral Investig, 2014 Dec;18(9):2103-12.
    PMID: 24549764 DOI: 10.1007/s00784-014-1207-4
    The aim of this study was to investigate the immunodulatory properties of dental pulp stem cells derived from healthy (SCD) and inflamed pulp deciduous (SCDIP) tissues. The overall hypothesis is that SCDIP possess equal immune properties with SCD and could be used as an alternative tissue source in regenerative medicine.
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