Displaying publications 41 - 60 of 78 in total

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  1. Reza Etemadi M, Ling KH, Zainal Abidin S, Chee HY, Sekawi Z
    PLoS One, 2017;12(5):e0176947.
    PMID: 28558071 DOI: 10.1371/journal.pone.0176947
    Human rhinovirus (HRV) is the common virus that causes acute respiratory infection (ARI) and is frequently associated with lower respiratory tract infections (LRTIs). We aimed to investigate whether HRV infection induces a specific gene expression pattern in airway epithelial cells. Alveolar epithelial cell monolayers were infected with HRV species B (HRV-B). RNA was extracted from both supernatants and infected monolayer cells at 6, 12, 24 and 48 hours post infection (hpi) and transcriptional profile was analyzed using Affymetrix GeneChip and the results were subsequently validated using quantitative Real-time PCR method. HRV-B infects alveolar epithelial cells which supports implication of the virus with LRTIs. In total 991 genes were found differentially expressed during the course of infection. Of these, 459 genes were up-regulated whereas 532 genes were down-regulated. Differential gene expression at 6 hpi (187 genes up-regulated vs. 156 down-regulated) were significantly represented by gene ontologies related to the chemokines and inflammatory molecules indicating characteristic of viral infection. The 75 up-regulated genes surpassed the down-regulated genes (35) at 12 hpi and their enriched ontologies fell into discrete functional entities such as regulation of apoptosis, anti-apoptosis, and wound healing. At later time points of 24 and 48 hpi, predominated down-regulated genes were enriched for extracellular matrix proteins and airway remodeling events. Our data provides a comprehensive image of host response to HRV infection. The study suggests the underlying molecular regulatory networks genes which might be involved in pathogenicity of the HRV-B and potential targets for further validations and development of effective treatment.
  2. Badamasi IM, Lye MS, Ibrahim N, Abdul Razaq NA, Ling KH, Stanslas J
    Pharmacogenomics J, 2021 Aug;21(4):498-509.
    PMID: 33731884 DOI: 10.1038/s41397-021-00228-6
    The polymorphisms of the 5HTR1A and 5HTR2A receptor genes (rs6295C/G and rs6311G/A) have been evaluated for association with SSRI treatment outcome in various populations with different results. The present study was carried out to determine the association between genotypes of HTR1A-rs6295 and HTR2A-rs6311 with SSRI treatment outcome among the ethnic Malay patients diagnosed with first-episode major depressive disorder (MDD). The patients were recruited from four tertiary hospitals in the Klang Valley region of Malaysia. Predefined efficacy phenotypes based on 25% (partial early response) and 50% (clinical efficacy response) reduction in Montgomery Asberg Depression Rating Scale-self Rated score (MADRS-S) were adopted for assessment of treatment efficacy in this study. Self-reporting for adverse effects (AE) was documented using the Patient Rated Inventory of Side Effect (PRISE) after treatment with SSRI for up to 6 weeks. Adjusted binary logistic regression between genotypes of the polymorphism obtained using sequencing technique with the treatment outcome phenotypes was performed. The 142 patients recruited were made up of 96 females (67.6%) and 46 males (32.4%). Clinical efficacy and Partial early response phenotypes were not significantly associated with genotypes of HTR1A and HTR2A polymorphism. The GG genotype of HTR2A polymorphism has decreased odds for dizziness (CNS) and increased odds for poor concentration. The GA genotype increases the odd for excessive sweating, diarrhoea, constipation and blurred vision. The CC genotype of HTR1A-rs6295 decreases the odd for nausea/vomiting and increases the odd for anxiety. Thus, some genotypes of HTR1A and HTR2A polymorphism were associated with SSRI treatment outcomes in ethnic Malay MDD patients.
  3. Mot YY, Moses EJ, Mohd Yusoff N, Ling KH, Yong YK, Tan JJ
    Cell Mol Neurobiol, 2023 Mar;43(2):469-489.
    PMID: 35103872 DOI: 10.1007/s10571-022-01201-y
    Traumatic brain injury (TBI) could result in life-long disabilities and death. Though the mechanical insult causes primary injury, the secondary injury due to dysregulated responses following neuronal apoptosis and inflammation is often the cause for more detrimental consequences. Mesenchymal stromal cell (MSC) has been extensively investigated as the emerging therapeutic for TBI, and the functional properties are chiefly attributed to their secretome, especially the exosomes. Delivering these nanosize exosomes have shown to ameliorate post-traumatic injury and restore brain functions. Recent technology advances also allow engineering MSC-derived exosomes to carry specific biomolecules of interest to augment their therapeutic outcome. In this review, we discuss the pathophysiology of TBI and summarize the recent progress in the applications of MSCs-derived exosomes, the roles and the signalling mechanisms underlying the protective effects in the treatment of the TBI.
  4. Lee YL, Ting TH, Lim CT, Arrumugam-Arthini C, Karuppiah T, Ling KH
    J Pediatr Endocrinol Metab, 2023 Oct 26;36(10):988-992.
    PMID: 37621150 DOI: 10.1515/jpem-2023-0171
    OBJECTIVES: PAX4 (Paired box 4), a transcription factor crucial in pancreatic beta cell development and function, is a rare cause of maturity-onset diabetes of the young (MODY). What is new? A novel PAX4 variant is verified by family segregation study to be likely pathogenic. A child below 10 years of age diagnosed to have PAX4-MODY, differing from previously reported paediatric cases diagnosed in adolescence.

    CASE PRESENTATION: A child with diabetes diagnosed at age 8 years, harbored a PAX4 variant, c.890G>A (p.Gly297Asp), initially classified as variant of uncertain significance. Eleven family members (7 adults and 4 children) with and without diabetes across 3 generations were genotyped. The variant co-segregated with diabetes or prediabetes across 3 generations of the family. The variant is reclassified as likely pathogenic according to standard guidelines.

    CONCLUSIONS: Genetic testing is essential to confirm PAX4-MODY as the presentation is variable even within the same family. PAX4 mutation needs to be considered in MODY genetic testing in Asian patients.

  5. Lam XJ, Xu B, Yeo PL, Cheah PS, Ling KH
    IBRO Neurosci Rep, 2023 Jun;14:407-418.
    PMID: 37388495 DOI: 10.1016/j.ibneur.2023.04.002
    Bipolar disorder (BD) is one of the major psychiatric diseases in which the impairment of mitochondrial functions has been closely connected or associated with the disease pathologies. Different lines of evidence of the close connection between mitochondria dysfunction and BD were discussed with a particular focus on (1) dysregulation of energy metabolism, (2) effect of genetic variants, (3) oxidative stress, cell death and apoptosis, (4) dysregulated calcium homeostasis and electrophysiology, and (5) current as well as potential treatments targeting at restoring mitochondrial functions. Currently, pharmacological interventions generally provide limited efficacy in preventing relapses or recovery from mania or depression episodes. Thus, understanding mitochondrial pathology in BD will lead to novel agents targeting mitochondrial dysfunction and formulating new effective therapy for BD.
  6. Azmi N, Mustaffa Al Bakri SS, Khor W, Hamzah SN, Ferdaos N, Ling KH, et al.
    IBRO Neurosci Rep, 2023 Jun;14:235-243.
    PMID: 37388489 DOI: 10.1016/j.ibneur.2023.01.003
    Full-term amniotic fluid stem cell (AFSC) is an underexplored reserve of broadly multipotent stem cells with potential applications in cell replacement therapy. One aspect worth exploring is the potential of AFSCs to differentiate into neural lineages. Previously, we have shown that full-term AFSC lines established from term gestation amniotic fluid, known as R3 and R2, differentiated into neural lineage through the monolayer adherent method suggesting their neurogenic potential. The neural commitment of the cells through the formation of multicellular aggregates has never been shown before. Here, we explored the ability of R3 to commit to neural fate via the formation of three-dimensional multicellular aggregates, namely embryoid bodies (EBs) and neurospheres, exhibiting distinct characteristics resembling EBs and neurospheres as obtained from other published pluripotent and neural stem cells (NSCs), respectively. Different cell seeding densities of the cells cultured in their respective induction medium generated two distinct types of aggregates with the appropriate sizes for EBs (300-350 µm) and neurospheres (50-100 µm). The neurospheres expressed a significantly high level of Nestin than EBs. However, EBs stained positive for TUJ1, suggesting the presence of early post-mitotic neurons representing the ectodermal lineage. In contrast, the presence of the NSC population in neurosphere culture was validated with positive expression of Sox1. Notably, dissociated cells from both aggregates differentiated into MAP2-positive neural cells, highlighting the ability of both types of multicellular aggregates to commit to the neural fate. In conclusion, this study highlights the first evidence of neurosphere formation from full-term AFSCs in addition to neural fate commitment via EBs formation. Findings from this study allow researchers to select the suitable approach for neural cell generation and expansion according to research needs.
  7. Mansor NI, Ling KH, Rosli R, Hassan Z, Adenan MI, Nordin N
    J Alzheimers Dis, 2023;94(s1):S21-S44.
    PMID: 37334592 DOI: 10.3233/JAD-221233
    BACKGROUND: Centella asiatica (L.) (C. asiatica) is commonly known in South East and South East Asia communities for its nutritional and medicinal benefits. Besides being traditionally used to enhance memory and accelerate wound healing, its phytochemicals have been extensively documented for their neuroprotective, neuroregenerative, and antioxidant properties.

    OBJECTIVE: The present study aims to investigate the effects of a standardized raw extract of C. asiatica (RECA) on hydrogen peroxide (H2O2)-induced oxidative stress and apoptotic death in neural-like cells derived from mouse embryonic stem (ES) cell line.

    METHODS: A transgenic mouse ES cell (46C) was differentiated into neural-like cells using 4-/4+ protocol with addition of all-trans retinoic acid. These cells were then exposed to H2O2 for 24 h. The effects of RECA on H2O2-induced neural-like cells were assessed through cell viability, apoptosis, and reactive oxygen species (ROS) assays, as well as neurite length measurement. The gene expression levels of neuronal-specific and antioxidant markers were assessed by RT-qPCR analysis.

    RESULTS: Pre-treatment with H2O2 for 24 hours, in a dose-dependent manner, damaged neural-like cells as marked by a decrease in cell viability, substantial increase in intracellular ROS accumulation, and increase in apoptotic rate compared to untreated cells. These cells were used to treat with RECA. Treatment with RECA for 48 h remarkably restored cell survival and promoted neurite outgrowth in the H2O2- damaged neurons by increasing cell viability and decreasing ROS activity. RT-qPCR analysis revealed that RECA upregulated the level of antioxidant genes such as thioredoxin-1 (Trx-1) and heme oxygenase-1 (HO-1) of treated cells, as well as the expression level of neuronal-specific markers such as Tuj1 and MAP2 genes, suggesting their contribution in neuritogenic effect.

    CONCLUSION: Our findings indicate that RECA promotes neuroregenerative effects and exhibits antioxidant properties, suggesting a valuable synergistic activity of its phytochemical constituents, thus, making the extract a promising candidate in preventing or treating oxidative stress-associated Alzheimer's disease.

  8. Ijabi R, Kaminsky ZA, Roozehdar P, Ijabi J, Moradi-Sardareh H, Ling KH, et al.
    Curr Med Chem, 2023 Sep 15.
    PMID: 37724672 DOI: 10.2174/0929867331666230915103147
    BACKGROUND: Epilepsy and intraventricular-cerebral hemorrhage is a common complication irreversible in preterm infants. Inflammation leads to an increase in intracellular calcium, acidosis, and oxygen usage, and finally, may damage brain cells. Increases in HIF-1a and HVCN1 can reduce the complications of oxygen consumption and acidosis in infants with intraventricular hemorrhage (IVH). On the other hand, decreases in S100B can shield nerve cells from apoptosis and epilepsy by reducing brain damage.

    OBJECTIVE: In this research, we investigated how miR-138-siRNAs-HIF-1a and miR-21-siRNAs-HVCN1 affect apoptosis in hypoxic mice.

    METHODS: On the first and third days after delivery, the YKL40, HIF-1a, HVCN1, and S100b genes were compared between two groups of preterm infants with and without maternal inflammation. Afterward, the miRNAs were transfected into cell lines to monitor variations in YKL40, HIF-1a, HVCN1, and S100b gene expression and nerve cell apoptosis. We changed the expression of S100b, HVCN1, and HIF-1a genes by using specific siRNAs injected into mice. Using real-time PCR, Western blotting, flow cytometry (FCM), and immunofluorescence, and changes in gene expression were evaluated (IHC).

    RESULTS: HVCN1 gene expression showed a strong negative correlation with epilepsy in both groups of infants (P<0.001). Significant correlations between epilepsy and the expression levels of the S100b, YKL40, and HIF-1a genes were found (P<0.001). According to FCM, after transfecting miRNA-431 and miRNA-34a into cell lines, the apoptosis index (A.I.) were 41.6 3.3 and 34.5 5.2%, respectively, while the A.I. were 9.6 2.7 and 7.1 4.2% after transfecting miRNA-21 and miRNA-138. MiR-138-siRNAs-HIF-1a and miR-21-siRNAs-HVCN1 were simultaneously injected into hypoxic mice, and IHC double-labeling revealed that this reduced apoptosis and seizures compared to the hypoxic group.

    CONCLUSION: Our findings demonstrate that miR-138-siRNAs-HIF-1a and miR-21-siRNAs-HVCN1 injections prevent cerebral ischemia-induced brain damage in hypoxia mice by increasing HVCN1 and HIF-1a and decreasing S100b, which in turn lessens apoptosis and epilepsy in hypoxic mice.

  9. Lee SS, Subramaniam R, Tusimin M, Ling KH, Rahim KF, Loh SP
    Nutr Res Pract, 2021 Aug;15(4):492-503.
    PMID: 34349882 DOI: 10.4162/nrp.2021.15.4.492
    BACKGROUND/OBJECTIVES: Recently, the recommended nutrient intakes (RNI) for vitamin D for Malaysian aged 1-70 yrs has been revised from 5 µg/day to 15 µg/day. This study is aimed to assess the adequacy of vitamin D intake based on revised RNI and to recommend several dietary strategies to increase total vitamin D intake.

    SUBJECTS/METHODS: Vitamin D intake from both food and supplement of 217 pregnant women was assessed using a validated food frequency questionnaire. Hypothetical effect of expanded supplementation and food fortifications strategies were modelled using the consumption data.

    RESULTS: The results revealed that more than half (67.7%) of pregnant women had inadequate vitamin D intake (RNI < 15 µg/day). The modelling results demonstrated the potential of universal provision of 10 µg/day of multivitamins supplements in increasing vitamin D intake. Moreover, mandatory fortification of both milk and malted drink at single level of 5 µg/serving would lead to increase in vitamin D intake of Malaysians, particularly pregnant women.

    CONCLUSIONS: The outcome of this study can be used as a reference for public health professionals to re-evaluate the existing Malaysian food fortification policies and supplementation recommendation for vitamin D for pregnant women.

  10. Azimzadeh M, Mohd Azmi MAN, Reisi P, Cheah PS, Ling KH
    MethodsX, 2024 Jun;12:102544.
    PMID: 38283759 DOI: 10.1016/j.mex.2023.102544
    In vivo extracellular field potential recording is a commonly used technique in modern neuroscience research. The success of long-term electrophysiological recordings often depends on the quality of the implantation surgery. However, there is limited use of visually guided stereotaxic neurosurgery and the application of the eLab/ePulse electrophysiology system in rodent models. This study presents a practical and functional manual guide for surgical electrode implantation in rodent models using the eLab/ePulse electrophysiology system for recording and stimulation purposes to assess neuronal functionality and synaptic plasticity. The evaluation parameters included the input/output function (IO), paired-pulse facilitation or depression (PPF/PPD), long-term potentiation (LTP), and long-term depression (LTD).•Provides a detailed picture-guided procedure for conducting in vivo stereotaxic neurosurgery.•Specifically covers the insertion of hippocampal electrodes and the recording of evoked extracellular field potentials.
  11. Heidarzadehpilehrood R, Pirhoushiaran M, Binti Osman M, Ling KH, Abdul Hamid H
    Iran J Pharm Res, 2023;22(1):e139985.
    PMID: 38444712 DOI: 10.5812/ijpr-139985
    BACKGROUND: Polycystic ovary syndrome (PCOS) affects women of reproductive age globally with an incidence rate of 5% - 26%. Growing evidence reports important roles for microRNAs (miRNAs) in the pathophysiology of granulosa cells (GCs) in PCOS.

    OBJECTIVES: The objectives of this study were to identify the top differentially expressed miRNAs (DE-miRNAs) and their corresponding targets in hub gene-miRNA networks, as well as identify novel DE-miRNAs by analyzing three distinct microarray datasets. Additionally, functional enrichment analysis was performed using bioinformatics approaches. Finally, interactions between the 5 top-ranked hub genes and drugs were investigated.

    METHODS: Using bioinformatics approaches, three GC profiles from the gene expression omnibus (GEO), namely gene expression omnibus series (GSE)-34526, GSE114419, and GSE137684, were analyzed. Targets of the top DE-miRNAs were predicted using the multiMiR R package, and only miRNAs with validated results were retrieved. Genes that were common between the "DE-miRNA prediction results" and the "existing tissue DE-mRNAs" were designated as differentially expressed genes (DEGs). Gene ontology (GO) and pathway enrichment analyses were implemented for DEGs. In order to identify hub genes and hub DE-miRNAs, the protein-protein interaction (PPI) network and miRNA-mRNA interaction network were constructed using Cytoscape software. The drug-gene interaction database (DGIdb) database was utilized to identify interactions between the top-ranked hub genes and drugs.

    RESULTS: Out of the top 20 DE-miRNAs that were retrieved from the GSE114419 and GSE34526 microarray datasets, only 13 of them had "validated results" through the multiMiR prediction method. Among the 13 DE-miRNAs investigated, only 5, namely hsa-miR-8085, hsa-miR-548w, hsa-miR-612, hsa-miR-1470, and hsa-miR-644a, demonstrated interactions with the 10 hub genes in the hub gene-miRNA networks in our study. Except for hsa-miR-612, the other 4 DE-miRNAs, including hsa-miR-8085, hsa-miR-548w, hsa-miR-1470, and hsa-miR-644a, are novel and had not been reported in PCOS pathogenesis before. Also, GO and pathway enrichment analyses identified "pathogenic E. coli infection" in the Kyoto encyclopedia of genes and genomes (KEGG) and "regulation of Rac1 activity" in FunRich as the top pathways. The drug-hub gene interaction network identified ACTB, JUN, PTEN, KRAS, and MAPK1 as potential targets to treat PCOS with therapeutic drugs.

    CONCLUSIONS: The findings from this study might assist researchers in uncovering new biomarkers and potential therapeutic drug targets in PCOS treatment.

  12. Lee YL, Ting TH, Lim CT, Thilakavathy K, Musa NH, Ling KH
    PMID: 38647408 DOI: 10.4274/jcrpe.galenos.2024.2023-12-1
    IGSF1 mutation is the commonest cause of mild to moderate isolated central congenital hypothyroidism and has an X-linked recessive inheritance, primarily affecting males. Other notable clinical features are macroorchidism with delayed pubertal testosterone rise, large birth weight, increased body mass index, low prolactin, transient growth hormone deficiency and low prolactin. Two male siblings with central hypothyroidism were found to have a novel IGSF1 c.3467T>A variant that was likely pathogenic based on the family segregation study. The proband, aged 3 years presented at 18 days old with prolonged jaundice while his 16-year-old brother was only detected to have central hypothyroidism after the proband's genetic analysis result was known. Both siblings were obese, had large birth weights, macroorchidism and low prolactin. The proband's brother had intellectual disability while the proband had normal development. This case study highlights the importance of evaluation for the IGSF1 variant in patients with unexplained central hypothyroidism, especially when accompanied by X-linked inheritance and macroorchidism. Family segregation analysis allows detection of other affected family members or carriers who may also benefit from thyroxine treatment.
  13. Huang T, Lam XJ, Lim CT, Jusoh N, Fakurazi S, Cheah PS, et al.
    J Intellect Disabil, 2024 Nov 13.
    PMID: 39533897 DOI: 10.1177/17446295241299160
    Down syndrome (DS), characterised by compromised brain development and intellectual challenges, often manifests Alzheimer's disease (AD) -like symptoms. Utilising the Web of Science Core Collection (WOSCC) database from January 1, 2000, to July 31, 2023, we conducted a comprehensive bibliometric analysis using VOSviewer, CiteSpace, and the R package "bibliometrix." Analyses included co-authorship, co-citation, co-occurrence, cooperative network, reference, and keyword burst citation. Analysing 5,082 papers, the U.S. demonstrated prominence with the highest number of research organisations and citations. Keyword analysis revealed promising research areas, including "Alzheimer's disease," "development," "inflammation," and "neurogenesis". This 22-year survey of the brain with trisomy 21 research unveils key trends, contributors, and focal areas in DS neuropathogenesis. Notably, Alzheimer 's-related genes and proteins play a pervasive role in DS neuropathological processes across patients' lifespans. The study contributes foundational knowledge for advancing research and care in the DS neuropathogenesis domain.
  14. Fish-Low CY, Balami AD, Than LTL, Ling KH, Mohd Taib N, Md Shah A, et al.
    J Infect Public Health, 2020 Feb;13(2):216-220.
    PMID: 31455598 DOI: 10.1016/j.jiph.2019.07.021
    BACKGROUND: Underestimation of leptospirosis cases is happening in many countries. The most common factor of underreporting is misdiagnosis. Considering the limitations of direct detection of pathogen and serological diagnosis for leptospirosis, clinical features and blood tests though non-specific are usually referred in making presumptive diagnosis to decide disease management.

    METHODS: In this single-centre retrospective study, comparative analysis on clinical presentations and laboratory findings was performed between confirmed leptospirosis versus non-leptospirosis cases.

    RESULTS: In multivariate logistic regression evidenced by a Hosmer-Lemeshow significance value of 0.979 and Nagelkerke R square of 0.426, the predictors of a leptospirosis case are hypocalcemia (calcium <2.10mmol/L), hypochloremia (chloride <98mmol/L), and eosinopenia (absolute eosinophil count <0.040×109/L). The proposed diagnostic scoring model has a discriminatory power with area under the curve (AUC) 0.761 (p<0.001). A score value of 6 reflected a sensitivity of 0.762, specificity of 0.655, a positive predictive value of 0.38, negative predictive value of 0.91, a positive likelihood ratios of 2.21, and a negative likelihood ratios of 0.36.

    CONCLUSION: With further validation in clinical settings, implementation of this diagnostic scoring model is helpful to manage presumed leptospirosis especially in the absence of leptospirosis confirmatory tests.

  15. Seth EA, Lee HC, Yusof HHBM, Nordin N, Cheah YK, Ho ETW, et al.
    PLoS One, 2020;15(7):e0236826.
    PMID: 32730314 DOI: 10.1371/journal.pone.0236826
    Down syndrome (DS), is the most common cause of intellectual disability, and is characterized by defective neurogenesis during perinatal development. To identify metabolic aberrations in early neurogenesis, we profiled neurospheres derived from the embryonic brain of Ts1Cje, a mouse model of Down syndrome. High-throughput phenotypic microarray revealed a significant decrease in utilisation of 17 out of 367 substrates and significantly higher utilisation of 6 substrates in the Ts1Cje neurospheres compared to controls. Specifically, Ts1Cje neurospheres were less efficient in the utilisation of glucose-6-phosphate suggesting a dysregulation in the energy-producing pathway. T Cje neurospheres were significantly smaller in diameter than the controls. Subsequent preliminary study on supplementation with 6-phosphogluconic acid, an intermediate of glucose-6-phosphate metabolism, was able to rescue the Ts1Cje neurosphere size. This study confirmed the perturbed pentose phosphate pathway, contributing to defects observed in Ts1Cje neurospheres. We show for the first time that this comprehensive energetic assay platform facilitates the metabolic characterisation of Ts1Cje cells and confirmed their distinguishable metabolic profiles compared to the controls.
  16. Mansor NI, Ntimi CM, Abdul-Aziz NM, Ling KH, Adam A, Rosli R, et al.
    Bosn J Basic Med Sci, 2021 Feb 01;21(1):98-110.
    PMID: 32156249 DOI: 10.17305/bjbms.2020.4639
    One of the strategies in the establishment of in vitro oxidative stress models for neurodegenerative diseases, such as Alzheimer's disease (AD), is to induce neurotoxicity by amyloid beta (Aβ) peptides in suitable neural cells. Presently, data on the neurotoxicity of Aβ in neural cells differentiated from stem cells are limited. In this study, we attempted to induce oxidative stress in transgenic 46C mouse embryonic stem cell-derived neurons via treatment with Aβ peptides (Aβ1-42 and Aβ25-35). 46C neural cells were generated by promoting the formation of multicellular aggregates, embryoid bodies in the absence of leukemia inhibitory factor, followed by the addition of all-trans retinoic acid as the neural inducer. Mature neuronal cells were exposed to different concentrations of Aβ1-42 and Aβ25-35 for 24 h. Morphological changes, cell viability, and intracellular reactive oxygen species (ROS) production were assessed. We found that 100 µM Aβ1-42 and 50 µM Aβ25-35 only promoted 40% and 10%, respectively, of cell injury and death in the 46C-derived neuronal cells. Interestingly, treatment with each of the Aβ peptides resulted in a significant increase of intracellular ROS activity, as compared to untreated neurons. These findings indicate the potential of using neurons derived from stem cells and Aβ peptides in generating oxidative stress for the establishment of an in vitro AD model that could be useful for drug screening and natural product studies.
  17. Lye MS, Tor YS, Tey YY, Shahabudin A, Loh SP, Ibrahim N, et al.
    J Mol Neurosci, 2021 May;71(5):981-990.
    PMID: 33034825 DOI: 10.1007/s12031-020-01719-0
    Heritability of major depressive disorder (MDD) is between 36 and 44%, suggesting that up to nearly half of the phenotypic variability is attributable to genes. A number of genetic polymorphisms have been shown to predispose certain individuals to depression. Of particular interest are the polymorphisms of the vitamin D receptor (VDR) gene. Although the VDR gene has been well characterized and a vast number of polymorphisms have been identified, the association between BsmI (rs1544410), ApaI (rs7975232) and TaqI (rs731236) single-nucleotide polymorphisms (SNPs), together with their haplotypes, and MDD risk have yet to be established. We conducted a matched case-control study with a total of 600 participants comprising 300 major depressive disorder (MDD) cases and 300 controls matched by age, gender and ethnicity in a 1:1 ratio, in four public hospitals in Kuala Lumpur and Selangor. Three adjacent SNPs of the VDR gene-BsmI (rs1544410), ApaI (rs7975232) and TaqI (rs731236)-were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Odds ratios and 95% confidence intervals (CIs) were obtained from conditional logistic regression using Stata 16. Linkage disequilibrium and haplotype association with MDD were analyzed using the online SNPStats program. None of the genotypes of the three SNPs was significantly associated with risk of developing MDD after adjusting for confounding factors. However, the TAC (BAt) haplotype was associated with increased odds of MDD (adjusted OR = 2.17, 95% CI = 1.30-3.61, p = 0.003) using CCT (baT) as reference haplotype. The findings suggest that the BsmI-ApaI-TaqI TAC (BAt) haplotype of the VDR gene increases susceptibility to MDD.
  18. Zainal Abidin S, Abbaspourbabaei M, Ntimi CM, Siew WH, Pike-See C, Rosli R, et al.
    Malays J Med Sci, 2014 Dec;21(Spec Issue):27-33.
    PMID: 25941460 MyJurnal
    MicroRNAs (miRNAs) have a crucial role in gene expression regulation and protein synthesis, especially in the central nervous system. In developing mouse embryos a novel miRNA, miR-3099, is highly expressed, particularly in the central nervous system. This study aims to determine the expression of miR-3099 during cellular differentiation of 46C mouse embryonic stem cells after neural induction with N2/B27 medium.
  19. Lim CW, Hamanaka G, Liang AC, Chan SJ, Ling KH, Lo EH, et al.
    Neurotoxicology, 2024 Aug 28;105:10-20.
    PMID: 39209271 DOI: 10.1016/j.neuro.2024.08.004
    JAK-STAT signaling cascade has emerged as an ideal target for the treatment of myeloproliferative diseases, autoimmune diseases, and neurological disorders. Ruxolitinib (Rux), is an orally bioavailable, potent and selective Janus-associated kinase (JAK) inhibitor, proven to be effective to target activated JAK-STAT pathway in the diseases previously described. Unfortunately, limited studies have investigated the potential cytotoxic profile of Rux on other cell populations within the heterogenous CNS microenvironment. Two stem and progenitor cell populations, namely the oligodendrocyte precursor cells (OPCs) and neural stem/progenitor cells (NSPCs), are important for long-term maintenance and post-injury recovery response of the CNS. In light of the limited evidence, this study sought to investigate further the effect of Rux on proliferating and differentiating OPCs and NSPCs populations. In the present study, cultured rat OPCs and NSPCs were treated with various concentrations of Rux, ranging from 2 μM to 20 μM. The effect of Rux on proliferating OPCs (PDGF-R-α+) and proliferating NSPCs (nestin+) was assessed via a 3-day Rux treatment, whereas its effect on differentiating OPCs (MBP+/PDGF-R-α+) and differentiating NSPCs (neurofilament+) was assessed after a 7-day treatment. Cytotoxicity of Rux was also assessed on OPC populations by examining its influence on cell death and DNA synthesis via YO-PRO-1/PI dual-staining and BrdU assay, respectively. The results suggest that Rux at a dosage above 10 μM reduces the number proliferating OPCs, likely via the induction of apoptosis. On the other hand, Rux treatment from 2.5 μM to 20 μM significantly reduces the number of differentiating OPCs by inducing necrosis. Meanwhile, Rux treatment has no observable untoward impact on NSPC cultures within the dosage range tested. Taken together, OPCs appears to be more vulnerable to the dosage effect of Rux, whereas NSPCs are not significantly impacted by Rux, suggesting a differential mechanism of actions of Rux on the cell types.
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