Cross-cultural adaptation and psychometric properties of the Malay version of parenting and child tooth brushing assessment (M-PACTA).

BACKGROUND: Malaysian preschool children continue to exhibit a high prevalence of dental caries and poor oral hygiene. There is a need to gain an in-depth understanding of oral hygiene habits and design suitable interventions to improve oral hygiene in early childhood. OBJECTIVE: To cross-culturally adapt and determine the psychometric properties of the Malay-translated Parenting and Child Tooth Brushing Assessment questionnaire (M-PACTA). METHODOLOGY: This cross-sectional study involved face and content validation, and forward and back-translation of PACTA. The M-PACTA was then tested for reliability and construct validity on 150 Malaysian parents of children aged 5 to 6 years old. RESULTS: Face validity indicated that the M-PACTA items were clear and easy to understand. For content validity, some words had to be modified in accordance with the recommendations of the expert committees to make it more coherent to Malaysians. Some statements in the parental knowledge scales were modified according to the guidelines applicable in Malaysia. The content comparison of the back translation with the adapted PACTA revealed that all items were semantic and linguistically equivalent. Exploratory factor analyses of M-PACTA suggested a two-factor structure for three scales including child behaviour scale ('non-compliance' and 'avoidance behaviour'), parental attitudes ('lack of concern' and 'attitude of care'), and parental knowledge ('general tooth brushing knowledge' and 'awareness of tooth brushing care') while for the parental strategy scale, three-factor structure was extracted including 'routine positive methods', 'uncommon positive methods', and 'negative methods'. Internal consistencies for all scales were good (α > 0.9). CONCLUSION: M-PACTA did not replicate the construct of the original PACTA. Nonetheless, M-PACTA demonstrated good construct validity, internal consistency reliability, and test-retest reliability within Malaysian context.

Study on intestinal parasitic infections and gut microbiota in cancer patients at a tertiary teaching hospital in Malaysia.

Intestinal parasitic infections (IPIs) can lead to significant morbidity and mortality in cancer patients. While they are unlikely to cause severe disease and are self-limiting in healthy individuals, cancer patients are especially susceptible to opportunistic parasitic infections. The gut microbiota plays a crucial role in various aspects of health, including immune regulation and metabolic processes. Parasites occupy the same environment as bacteria in the gut. Recent research suggests intestinal parasites can disrupt the normal balance of the gut microbiota. However, there is limited understanding of this co-infection dynamic among cancer patients in Malaysia. A study was conducted to determine the prevalence and relationship between intestinal parasites and gut microbiota composition in cancer patients. Stool samples from 134 cancer patients undergoing active treatment or newly diagnosed were collected and examined for the presence of intestinal parasites and gut microbiota composition. The study also involved 17 healthy individuals for comparison and control. Sequencing with 16S RNA at the V3-V4 region was used to determine the gut microbial composition between infected and non-infected cancer patients and healthy control subjects. The overall prevalence of IPIs among cancer patients was found to be 32.8%. Microsporidia spp. Accounted for the highest percentage at 20.1%, followed by Entamoeba spp. (3.7%), Cryptosporidium spp. (3.0%), Cyclospora spp. (2.2%), and Ascaris lumbricoides (0.8%). None of the health control subjects tested positive for intestinal parasites. The sequencing data analysis revealed that the gut microbiota diversity and composition were significantly different in cancer patients than in healthy controls (p < 0.001). A significant dissimilarity was observed in the bacterial composition between parasite-infected and non-infected patients based on Bray-Curtis (p = 0.041) and Jaccard (p = 0.021) measurements. Bacteria from the genus Enterococcus were enriched in the parasite-infected groups, while Faecalibacterium prausnitzii reduced compared to non-infected and control groups. Further analysis between different IPIs and non-infected individuals demonstrated a noteworthy variation in Entamoeba-infected (unweighted UniFrac: p = 0.008), Cryptosporidium-infected (Bray-Curtis: p = 0.034) and microsporidia-infected (unweighted: p = 0.026; weighted: p = 0.019; Jaccard: p = 0.031) samples. No significant dissimilarity was observed between Cyclospora-infected groups and non-infected groups. Specifically, patients infected with Cryptosporidium and Entamoeba showed increased obligate anaerobic bacteria. Clostridiales were enriched with Entamoeba infections, whereas those from Coriobacteriales decreased. Bacteroidales and Clostridium were found in higher abundance in the gut microbiota with Cryptosporidium infection, while Bacillales decreased. Additionally, bacteria from the genus Enterococcus were enriched in microsporidia-infected patients. In contrast, bacteria from the Clostridiales order, Faecalibacterium, Parabacteroides, Collinsella, Ruminococcus, and Sporosarcina decreased compared to the non-infected groups. These findings underscore the importance of understanding and managing the interactions between intestinal parasites and gut microbiota for improved outcomes in cancer patients.

Assessing modalities used to alleviate postoperative pain in children receiving dental treatment under general anaesthesia: a systematic review.

Postoperative pain is generally a novel experience among paediatric patients. Topical anaesthetics, distraction procedures, and buffering of anaesthetic solutions have been used in reducing the postoperative pain. In this review, the authors assessed various modalities used to alleviate postoperative pain in children's dental treatment under general anaesthesia. Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) protocol were strictly adhered to in this systematic review. Specific keywords including postoperative pain, general anaesthesia, children, and dental extraction were used in the search for relevant randomized control trial studies in Web of Science, Scopus and PubMed, and included articles published until June 2021. From a total of 191 abstracts, 21 were reviewed. From the six studies with the usage of non-steroidal anti-inflammatory drugs (NSAIDs) alone or in combination with paracetamol, four observed that the preoperative use of NSAIDs alone or in combination was better than paracetamol alone, one discovered preoperative intravenous paracetamol was better than postoperative intravenous paracetamol, and the remaining study found no difference among various groups. Of two studies comparing the usage of non-steroidal anti-inflammatory drugs with opioid analgesics, one stated intravenous fentanyl in combination was better, while the other study found no difference among groups. The results obtained in this review can be utilized by physicians to control postoperative pain in children undergoing dental treatment under general anaesthesia.

The Abeer Children Dental Anxiety Scale (ACDAS) cross-cultural adaptation and validity of self-report measures in the Malaysian Children Context (MY-ACDAS).

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.

Retrospective analysis of dental treatment under general anesthesia among children with early childhood caries in Malaysia.

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.

A comparison study of dental pulp stem cells derived from healthy and orthodontically intruded human permanent teeth for mesenchymal stem cell characterisation.

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.

Antiproliferative effects of dried Moringa oleifera leaf extract on human Wharton's Jelly mesenchymal stem cells.

Mesenchymal stem cells (MSCs) have seen an elevated use in clinical works like regenerative medicine. Its potential therapeutic properties increases when used in tandem with complementary agents like bio-based materials. Therefore, the present study is the first to investigate the cytotoxicity of a highly valued medicinal plant, Moringa oleifera, on human Wharton's Jelly mesenchymal stem cells (hWJMSCs) and its effects on the cells' gene expression when used as a pre-treatment agent in vitro. M. oleifera leaves (MOL) were dried and subjected to UHPLC-QTOF/MS analysis, revealing several major compounds like apigenin, kaempferol, and quercetin in the MOL, with various biological activities like antioxidant and anti-cancer properties. We then treated the hWJMSCs with MOL and noticed a dose-dependant inhibition on the cells' proliferation. RNA-sequencing was performed to explain the possible mechanism of action and revealed genes like PPP1R1C, SULT2B1, CDKN1A, mir-154 and CCNB1, whose expression patterns were closely associated with the negative cell cycle regulation and cell cycle arrest process. This is also evident from gene set enrichment analysis where the GO and KEGG terms for down-regulated pathways were closely related to the cell cycle regulation. The Ingenuity pathway analysis (IPA) software further predicted the significant activation of (p < 0.05, z-score > 2) of the G2/M DNA damage checkpoint regulation pathway. The present study suggests that MOL exhibits an antiproliferative effect on hWJMSCs via cell cycle arrest and apoptotic pathways. We believe that this study provides an important baseline reference for future works involving MOL's potential to accompany MSCs for clinical works. Future works can take advantage of the cell's strong anti-cancer gene expression found in this study, and evaluate our MOL treatment on various cancer cell lines.

Retention Evaluation of Fissure Sealants Applied Using Self-Etch and Conventional Acid-Etch Techniques: A Randomized Control Trial Among Schoolchildren.

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.

Spatial dispersal of Aedes albopictus mosquitoes captured by the modified sticky ovitrap in Selangor, Malaysia.

Dengue is a major mosquito-borne disease in many tropical and sub-tropical countries worldwide, with entomological surveillance and control activities as the key management approaches. This study aimed to explore the spatial dispersal of the vector Aedes albopictus, captured by the modified sticky ovitrap (MSO) in residential areas with low-rise buildings in Selangor, Malaysia. Distribution maps were created and shown as temporally distinguished classes based on hotspot analysis by Getis-Ord; spatial autocorrelation assessed by semivariograms using the exponential Kernel function; and universal Kriging showing areas with estimated high and low vector densities. Distribution, hotspot and interpolated maps were analysed based on the total number of mosquitoes by month and week. All maps in the present study were generated and visualised in ArcMap. Spatial autocorrelation of Ae. albopictus based on the monthly occurrence of Ae. albopictus was found in March, April, October, November and December 2018, and when based on the weekly numbers, in weeks 1, 2, 3, 5, 7, 12, 14, 25, 26, 27, 31, 33, 42, 49 and 52. Semivariograms, based on the monthly and weekly numbers of Ae. albopictus, indicated spatial autocorrelation of the species extending between 50 and 70 m. The mosquito density maps reported in this study may provide beneficial information to facilitate implementation of more efficient entomological control activities.

Effects of cell cycle phases on the induction of dental pulp stem cells toward dopaminergic-like cells.

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 < 0.05) of DA-ergic molecular cues compared to those from the remaining time points. Further investigations in terms of protein expression and DA-release assays also revealed a similar phenomenon (p < 0.05). These findings are expected to provide vital information for consideration in improving standard operating procedures in future cell transplantation work. Copyright © 2017 John Wiley & Sons, Ltd.

Effect of dental pulp stem cells in MPTP-induced old-aged mice model.

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'.

Generation of functional hepatocyte-like cells from human deciduous periodontal ligament stem cells.

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.

Aspirin Enhances Osteogenic Potential of Periodontal Ligament Stem Cells (PDLSCs) and Modulates the Expression Profile of Growth Factor-Associated Genes in PDLSCs.

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.

ReNCell VM conditioned medium enhances the induction of dental pulp stem cells into dopaminergic like cells.

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 < 0.05) in pre-treated cells. Similar observations were detected at the protein level. The results demonstrate for the first time that SHED pre-conditioning enhances neurological potential and we suggest that cells should be primed to their respective environment prior to transplantation.

Expression patterns of immune genes in long-term cultured dental stem cells.

BACKGROUND AND OBJECTIVES: 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. METHODS: Dental pulp stem cells from deciduous (SHED; n = 3) and permanent (DPSCs; n = 3) teeth as well as periodontal ligament stem cells (PDLSCs; n = 3) were cultured under identical culture condition. The immune properties of each cell lines were profiled at passage 2 [P2] and passage 9 [P9] as early and late passages, respectively. This was further validated at the protein level using the Luminex platform. RESULTS: A major shift of genes was noticed at P9 with SHED being the highest. SHED cultured at P9 displayed many genes representing pathogen recognition (P < 0.001), immune signalling (P < 0.001, pro-inflammatory (P < 0.001), anti-inflammatory (P < 0.001) and immune-related growth and stimulation factor (P < 0.001) as compared to DPSCs and PDLSCs. Surprisingly, SHED also expressed many cytotoxicity genes (P < 0.001). CONCLUSIONS: Communally, instabilities of immune genes from our findings suggest that long-term cultured cells may not be feasible for transplantation purposes. CLINICAL RELEVANCE: A complete biological characterization covering all major aspects including immune properties should be made as prerequisite criteria prior to the use of long-term cultured stem cells in clinical settings.

Differential expression of basal microRNAs' patterns in human dental pulp stem cells.

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.

Unique molecular signatures influencing the biological function and fate of post-natal stem cells isolated from different sources.

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.

Comparative analysis of cardiovascular development related genes in stem cells isolated from deciduous pulp and adipose tissue.

Human exfoliated deciduous teeth (SHED) and adipose stem cells (ASC) were suggested as alternative cell choice for cardiac regeneration. However, the true functionability of these cells toward cardiac regeneration is yet to be discovered. Hence, this study was carried out to investigate the innate biological properties of these cell sources toward cardiac regeneration. Both cells exhibited indistinguishable MSCs characteristics. Human stem cell transcription factor arrays were used to screen expression levels in SHED and ASC. Upregulated expression of transcription factor (TF) genes was detected in both sources. An almost equal percentage of >2-fold changes were observed. These TF genes fall under several cardiovascular categories with higher expressions which were observed in growth and development of blood vessel, angiogenesis, and vasculogenesis categories. Further induction into cardiomyocyte revealed ASC to express more significantly cardiomyocyte specific markers compared to SHED during the differentiation course evidenced by morphology and gene expression profile. Despite this, spontaneous cellular beating was not detected in both cell lines. Taken together, our data suggest that despite being defined as MSCs, both ASC and SHED behave differently when they were cultured in a same cardiomyocytes culture condition. Hence, vigorous characterization is needed before introducing any cell for treating targeted diseases.

Different isolation methods alter the gene expression profiling of adipose derived stem cells.

Human adipose stem cells (ASCs) has been in the limelight since its discovery as a suitable source of mesenchymal stem cells (MSCs) in regenerative medicine. Currently, two major techniques are used to isolate ASCs, namely liposuction and tissue biopsy. These two methods are relatively risk-free but the question as to which method could give a more efficient output remains unclear. Thus, this study was carried out to compare and contrast the output generated in regards to growth kinetics, differentiation capabilities in vitro, and gene expression profiling. It was found that ASCs from both isolation methods were comparable in terms of growth kinetics and tri-lineage differentiation. Furthermore, ASCs from both populations were reported as CD44(+), CD73(+), CD90(+), CD166(+), CD34(-), CD45(-) and HLA-DR(-). However, in regards to gene expression, a group of overlapping genes as well as distinct genes were observed. Distinct gene expressions indicated that ASCs (liposuction) has endoderm lineage propensity whereas ASCs (biopsy) has a tendency towards mesoderm/ectoderm lineage. This information suggests involvement in different functional activity in accordance to isolation method. In conclusion, future studies to better understand these gene functions should be carried out in order to contribute in the applicability of each respective cells in regenerative therapy.

Diverse effects of lead nitrate on the proliferation, differentiation, and gene expression of stem cells isolated from a dental origin.

Lead (Pb(2+)) exposure continues to be a significant public health problem. Therefore, it is vital to have a continuous epidemiological dataset for a better understanding of Pb(2+) toxicity. In the present study, we have exposed stem cells isolated from deciduous and permanent teeth, periodontal ligament, and bone marrow to five different types of Pb(2+) concentrations (160, 80, 40, 20, and 10 µM) for 24 hours to identify the adverse effects of Pb(2+) on the proliferation, differentiation, and gene expression on these cell lines. We found that Pb(2+) treatment altered the morphology and adhesion of the cells in a dose-dependent manner. There were no significant changes in terms of cell surface phenotypes. Cells exposed to Pb(2+) continued to differentiate into chondrogenesis and adipogenesis, and a severe downregulation was observed in osteogenesis. Gene expression studies revealed a constant expression of key markers associated with stemness (Oct 4, Rex 1) and DNA repair enzyme markers, but downregulation occurred with some ectoderm and endoderm markers, demonstrating an irregular and untimely differentiation trail. Our study revealed for the first time that Pb(2+) exposure not only affects the phenotypic characteristics but also induces significant alteration in the differentiation and gene expression in the cells.