Displaying publications 1 - 20 of 42 in total

Abstract:
Sort:
  1. Liew CC, Lau YL, Fong MY, Cheong FW
    Am J Trop Med Hyg, 2020 05;102(5):1068-1071.
    PMID: 32189613 DOI: 10.4269/ajtmh.19-0836
    Invasion of human erythrocytes by merozoites of Plasmodium knowlesi involves interaction between the P. knowlesi Duffy binding protein alpha region II (PkDBPαII) and Duffy antigen receptor for chemokines (DARCs) on the erythrocytes. Information is scarce on the binding level of PkDBPαII to different Duffy antigens, Fya and Fyb. This study aims to measure the binding level of two genetically distinct PkDBPαII haplotypes to Fy(a+b-) and Fy(a+b+) human erythrocytes using erythrocyte-binding assay. The binding level of PkDBPαII of Peninsular Malaysian and Malaysian Borneon haplotypes to erythrocytes was determined by counting the number of rosettes formed in the assay. Overall, the Peninsular Malaysian haplotype displayed higher binding activity than the Malaysian Borneon haplotype. Both haplotypes exhibit the same preference to Fy(a+b+) compared with Fy(a+b-), hence justifying the vital role of Fyb in the binding to PkDBPαII. Further studies are needed to investigate the P. knowlesi susceptibility on individuals with different Duffy blood groups.
    Matched MeSH terms: Receptors, Cell Surface/genetics*; Receptors, Cell Surface/immunology; Receptors, Cell Surface/metabolism
  2. Hassan FW, Mohd N
    Spec Care Dentist, 2021 Jan;41(1):92-97.
    PMID: 33125720 DOI: 10.1111/scd.12537
    BACKGROUND/AIM: Polycythemia rubra vera (PRV) is a myeloproliferative disease, which is characterized by the proliferation of all three major hematopoietic groups (erythrocytes, leucocytes and platelets). This hematological condition presented with different clinical manifestations depending on the thrombohemorrhagic status of the patient. It is suggested patient with preexisting PRV may suffer complication during periodontal treatment. Thus, this case would therefore demonstrate periodontal management outcome in PRV patient.

    CASE PRESENTATION: A 60-year-old Malay gentleman presented to the Periodontic Clinic, Universiti Kebangsaan Malaysia. He was a known case of primary PRV for the past 5 years. Intraoral examination showed generalized periodontal deep pockets ranging from 5 to 10 mm. He was diagnosed as Stage III Grade C periodontitis. Nonsurgical periodontal therapy was provided, followed by surgical correction of residual periodontal deep pockets on teeth 17, 11, and 23. He was reviewed at 4-month intervals for supportive periodontal therapy after stabilization of his periodontal condition.

    CONCLUSION: Polycythemia rubra vera (PRV) patients should have preoperative therapeutic control for more than 4 months and have been treated with myelosuppressive agents prior to periodontal surgery. Good oral hygiene and periodical supportive periodontal therapy are the key factors for successful periodontal treatment outcomes in well-controlled PRV patients.

    Matched MeSH terms: Receptors, Cell Surface
  3. Park YG, Choi J, Song I, Park SY, Seol JW, Jackson CJ
    Sains Malaysiana, 2017;46:1895-1902.
    Rheumatoid arthritis (RA) is a chronic disease characterized by inflammation of the joints and their lining or synovium. Previous studies showed that the synovium in RA patients is more hypoxic than normal synovium. Activated protein C (APC) has anticoagulant and anti-inflammatory effects and is highly expressed in the joints of RA patients. We examined the effect of APC on RA and normal synovial fibroblasts under hypoxic conditions. Human synovial fibroblasts were isolated from the synovial tissues of RA patients and normal controls and cells were exposed to recombinant APC under normoxic (21% oxygen) or hypoxic (1% oxygen) conditions. Cell proliferation was measured using MTT assays. Cell lysates and conditioned media were collected and assayed for matrix metalloproteinase (MMP)-2, MMP-9 and p38 using zymography and western blots. Proliferation of both normal and RA synovial fibroblasts dose-dependently increased after APC treatment in normoxic conditions. Under hypoxia, APC enhanced RA cell proliferation but had no effect on normal fibroblasts. MMP-2 production and activation were significantly augmented by APC in both cell types under normoxia and hypoxia conditions. However, activated MMP-2 was more reduced in cells under hypoxia than normoxia. APC substantially reduced the phosphorylation of p38 in normal and RA synovial fibroblasts under hypoxia. No difference in p38 phosphorylation was observed under normoxia. The receptor for APC, endothelial protein C receptor (EPCR), was elevated in normal fibroblasts under hypoxic conditions whereas in RA cells, EPCR was highly expressed under both normoxic and hypoxic conditions. We found that hypoxia enhanced the effect of APC on RA synovial fibroblasts through activation of MMP2 and inhibition of p38 phosphorylation. Our results suggested that APC may suppress joint destruction and progression of inflammation in a hypoxic RA environment.
    Matched MeSH terms: Receptors, Cell Surface
  4. Saifful Kamaluddin Muzakir, Shahidan Radiman
    Sains Malaysiana, 2011;40:1123-1127.
    Nanozarah zink oksida telah disintesis menggunakan afrons gas koloid sebagai acuan. Zink sulfat (ZnSO4.7H2O) dan gas ammonia digunakan sebagi bahan tindak balas. Masa pengeraman yang dikaji adalah 2 jam dan 18 jam. Daripada analisis mikroskop elektron imbasan, morfologi nanohelaian dapat diperhatikan dengan ketebalan helaian 125 nm hingga 200 nm. Daripada analisis spektroskopi ultra lembayung-boleh nampak, saiz purata yang dianggarkan bagi sampel nanozarah zink oksida yang disintesis dengan masa pengeraman 2 jam adalah 2.03 nm dan 2.1 nm untuk sampel yang dieramkan selama 18 jam.
    Matched MeSH terms: Receptors, Cell Surface
  5. Tukimat Lihan, Nur Fatin Khodri, Muzzneena Ahmad Mustapha, Zulfahmi Ali Rahman, Wan Mohd Razi Idris
    Sains Malaysiana, 2018;47:2241-2249.
    Aktiviti guna tanah di kawasan lembangan adalah salah satu faktor yang mendorong kepada kemerosotan kualiti air
    sungai akibat daripada hakisan tanih. Potensi hakisan tanih di kawasan lembangan Sungai Bilut, Raub, Pahang yang
    menjadi sumber bekalan air minuman utama di daerah Raub boleh ditentukan dengan menggunakan integrasi model
    Semakan Semula Persamaan Kehilangan Tanih Universal (RUSLE) dan Sistem Maklumat Geografi (GIS). Kajian ini
    bertujuan untuk menentukan potensi hakisan tanih dan faktor utama yang mempengaruhi kadar hakisan tanih. Kajian ini
    melibatkan penggunaan data sekunder yang terdiri daripada data hujan, data siri tanih dan topografi bagi menghasilkan
    faktor kehakisan hujan (R), kebolehhakisan tanih (K), serta panjang dan kecuraman cerun (LS). Faktor litupan tumbuhan
    (C) dan amalan pemuliharaan (P) pula dijana daripada imej satelit Landsat 8 (2014). Keputusan kajian menunjukkan
    nilai faktor R di kawasan kajian ialah 8927.68-9775.18 MJ mm ha-1 jam-1 tahun-1, nilai K ialah 0.036-0.500 tan jam-1
    MJ-1 mm-1, nilai LS ialah 0-514, nilai C ialah 0.03-0.80 dan nilai P ialah 0.1-0.7. Kawasan yang mempunyai potensi
    hakisan sangat rendah hingga rendah meliputi 81%, manakala potensi hakisan tanih sederhana hingga sangat tinggi
    meliputi 19% daripada keseluruhan kawasan kajian. Model yang dihasilkan mempunyai ketepatan sebanyak 81%. Faktor
    utama yang mempengaruhi berlakunya hakisan tanih di kawasan kajian adalah faktor topografi, litupan tumbuhan dan
    kebolehhakisan tanih. Keputusan menunjukkan analisis integrasi RUSLE dan GIS berpotensi dalam penentuan potensi
    hakisan tanih untuk kawasan luas yang mempunyai pelbagai jenis guna tanah, topografi dan jenis tanih.
    Matched MeSH terms: Receptors, Cell Surface
  6. Fong MY, Rashdi SA, Yusof R, Lau YL
    PLoS One, 2016;11(5):e0155627.
    PMID: 27195821 DOI: 10.1371/journal.pone.0155627
    BACKGROUND: Plasmodium knowlesi is a simian malaria parasite that has been reported to cause malaria in humans in Southeast Asia. This parasite invades the erythrocytes of humans and of its natural host, the macaque Macaca fascicularis, via interaction between the Duffy binding protein region II (PkDBPαRII) and the Duffy antigen receptor on the host erythrocytes. In contrast, the P. knowlesi gamma protein region II (PkγRII) is not involved in the invasion of P. knowlesi into humans. PkγRII, however, mediates the invasion of P. knowlesi into the erythrocytes of M. mulata, a non-natural host of P. knowlesi via a hitherto unknown receptor. The haplotypes of PkDBPαRII in P. knowlesi isolates from Peninsular Malaysia and North Borneo have been shown to be genetically distinct and geographically clustered. Also, the PkDBPαRII was observed to be undergoing purifying (negative) selection. The present study aimed to determine whether similar phenomena occur in PkγRII.

    METHODS: Blood samples from 78 knowlesi malaria patients were used. Forty-eight of the samples were from Peninsular Malaysia, and 30 were from Malaysia Borneo. The genomic DNA of the samples was extracted and used as template for the PCR amplification of the PkγRII. The PCR product was cloned and sequenced. The sequences obtained were analysed for genetic diversity and natural selection using MEGA6 and DnaSP (version 5.10.00) programmes. Genetic differentiation between the PkγRII of Peninsular Malaysia and North Borneo isolates was estimated using the Wright's FST fixation index in DnaSP (version 5.10.00). Haplotype analysis was carried out using the Median-Joining approach in NETWORK (version 4.6.1.3).

    RESULTS: A total of 78 PkγRII sequences was obtained. Comparative analysis showed that the PkγRII have similar range of haplotype (Hd) and nucleotide diversity (π) with that of PkDBPαRII. Other similarities between PkγRII and PkDBPαRII include undergoing purifying (negative) selection, geographical clustering of haplotypes, and high inter-population genetic differentiation (FST index). The main differences between PkγRII and PkDBPαRII include length polymorphism and no departure from neutrality (as measured by Tajima's D statistics) in the PkγRII.

    CONCLUSION: Despite the biological difference between PkγRII and PkDBPαRII, both generally have similar genetic diversity level, natural selection, geographical haplotype clustering and inter-population genetic differentiation index.

    Matched MeSH terms: Receptors, Cell Surface/genetics*
  7. Jambari NN, Liddell S, Martinez-Pomares L, Alcocer MJC
    PLoS One, 2021;16(4):e0249876.
    PMID: 33914740 DOI: 10.1371/journal.pone.0249876
    Ber e 1, a major Brazil nut allergen, has been successfully produced in the yeast Pichia pastoris expression system as homogenous recombinant Ber e 1 (rBer e 1) with similar physicochemical properties and identical immunoreactivity to its native counterpart, nBer e 1. However, O-linked glycans was detected on the P.pastoris-derived rBer e 1, which is not naturally present in nBer e 1, and may contribute to the allergic sensitisation. In this study, we addressed the glycosylation differences between P. pastoris-derived recombinant Ber e 1 and its native counterparts. We also determined whether this fungal glycosylation could affect the antigenicity and immunogenicity of the rBer e 1 by using dendritic cells (DC) as an immune cell model due to their role in modulating the immune response. We identified that the glycosylation occurs at Ser96, Ser101 and Ser110 on the large chain and Ser19 on the small polypeptide chain of rBer e 1 only. The glycosylation on rBer e 1 was shown to elicit varying degree of antigenicity by binding to different combination of human leukocyte antigens (HLA) at different frequencies compared to nBer e 1 when tested using human DC-T cell assay. However, both forms of Ber e 1 are weak immunogens based from their low response indexes (RI). Glycans present on rBer e 1 were shown to increase the efficiency of the protein recognition and internalization by murine bone marrow-derived dendritic cells (bmDC) via C-type lectin receptors, particularly the mannose receptor (MR), compared to the non-glycosylated nBer e 1 and SFA8, a weak allergenic 2S albumin protein from sunflower seed. Binding of glycosylated rBer e 1 to MR alone was found to not induce the production of IL-10 that modulates bmDC to polarise Th2 cell response by suppressing IL-12 production and DC maturation. Our findings suggest that the O-linked glycosylation by P. pastoris has a small but measurable effect on the in vitro antigenicity of the rBer e 1 compared to its non-glycosylated counterpart, nBer e 1, and thus may influence its applications in diagnostics and immunotherapy.
    Matched MeSH terms: Receptors, Cell Surface/metabolism
  8. Jantan I, Pisar MM, Idris MS, Taher M, Ali RM
    Planta Med, 2002 Dec;68(12):1133-4.
    PMID: 12494345
    Rubraxanthone and isocowanol isolated from Garcinia parvifolia Miq. were investigated for their inhibitory effects on platelet-activating factor (PAF) binding to rabbit platelets using 3H-PAF as a ligand. Rubraxanthone showed a strong inhibition with IC 50 value of 18.2 microM. The IC 50 values of macluraxanthone, 6-deoxyjacareubin, 2-(3-methylbut-2-enyl)-1,3,5-trihydroxyxanthone, 2-(3-methylbut-2-enyl)-1,3,5,6-tetrahydroxyxanthone and 1,3,5-trihydroxy-6,6'-dimethylpyrano(2',3':6,7)-4-(1,1-dimethylprop-2-enyl)-xanthone were also determined for comparison. In the course of our study on structure-activity relationship of xanthones, the results revealed that a geranyl group substituted at C-8 was beneficial to the binding while a hydroxylated prenyl group at C-4 resulted in a significant loss in binding to the PAF receptor.
    Matched MeSH terms: Receptors, Cell Surface/antagonists & inhibitors; Receptors, Cell Surface/metabolism*
  9. Watabe M, Arjunan SNV, Chew WX, Kaizu K, Takahashi K
    Phys Rev E, 2019 Jul;100(1-1):010402.
    PMID: 31499827 DOI: 10.1103/PhysRevE.100.010402
    We propose a computational method to quantitatively evaluate the systematic uncertainties that arise from undetectable sources in biological measurements using live-cell imaging techniques. We then demonstrate this method in measuring the biological cooperativity of molecular binding networks, in particular, ligand molecules binding to cell-surface receptor proteins. Our results show how the nonstatistical uncertainties lead to invalid identifications of the measured cooperativity. Through this computational scheme, the biological interpretation can be more objectively evaluated and understood under a specific experimental configuration of interest.
    Matched MeSH terms: Receptors, Cell Surface
  10. Wong CY, Cheong SK, Mok PL, Leong CF
    Pathology, 2008 Jan;40(1):52-7.
    PMID: 18038316
    AIMS: Adult human bone marrow contains a population of mesenchymal stem cells (MSC) that contributes to the regeneration of tissues such as bone, cartilage, muscle, tendon, and fat. In recent years, it has been shown that functional stem cells exist in the adult bone marrow, and they can contribute to renal remodelling or reconstitution of injured renal glomeruli, especially mesangial cells. The purpose of this study is to examine the ability of MSC isolated from human bone marrow to differentiate into mesangial cells in glomerular injured athymic mice.

    METHODS: MSC were isolated from human bone marrow mononuclear cells based on plastic adherent properties and expanded in vitro in the culture medium. Human mesenchymal stem cells (hMSC) were characterised using microscopy, immunophenotyping, and their ability to differentiate into adipocytes, chondrocytes, and osteocytes. hMSC were then injected into athymic mice, which had induced glomerulonephropathy (GN).

    RESULTS: Test mice (induced GN and infused hMSC) were shown to have anti-human CD105(+) cells present in the kidneys and were also positive to anti-human desmin, a marker for mesangial cells. Furthermore, immunofluorescence assays also demonstrated that anti-human desmin(+) cells in the glomeruli of these test mice were in the proliferation stage, being positive to anti-human Ki-67.

    CONCLUSIONS: These findings indicate that hMSC found in renal glomeruli differentiated into mesangial cells in vivo after glomerular injury occurred.

    Matched MeSH terms: Receptors, Cell Surface/metabolism
  11. Fong MY, Cheong FW, Lau YL
    Parasit Vectors, 2018 Sep 26;11(1):527.
    PMID: 30257710 DOI: 10.1186/s13071-018-3118-8
    BACKGROUND: The merozoite of the zoonotic Plasmodium knowlesi invades human erythrocytes via the binding of its Duffy binding protein (PkDBPαII) to the Duffy antigen on the eythrocytes. The Duffy antigen has two immunologically distinct forms, Fya and Fyb. In this study, the erythrocyte-binding assay was used to quantitatively determine and compare the binding level of PkDBPαII to Fya+/b+ and Fya+/b- human erythrocytes.

    RESULTS: In the erythrocyte-binding assay, binding level was determined by scoring the number of rosettes that were formed by erythrocytes surrounding transfected mammalian COS-7 cells which expressed PkDBPαII. The assay result revealed a significant difference in the binding level. The number of rosettes scored for Fya+/b+ was 1.64-fold higher than that of Fya+/b- (155.50 ± 34.32 and 94.75 ± 23.16 rosettes, respectively; t(6) = -2.935, P = 0.026).

    CONCLUSIONS: The erythrocyte-binding assay provided a simple approach to quantitatively determine the binding level of PkDBPαII to the erythrocyte Duffy antigen. Using this assay, PkDBPαII was found to display higher binding to Fya+/b+ erythrocytes than to Fya+/b- erythrocytes.

    Matched MeSH terms: Receptors, Cell Surface/genetics; Receptors, Cell Surface/metabolism*
  12. Benson MD, Khor CC, Gage PJ, Lehmann OJ
    Mol Vis, 2017;23:952-962.
    PMID: 29296075
    Purpose: To evaluate the ability of a targeted genome-wide association study (GWAS) to identify genes associated with central corneal thickness (CCT).

    Methods: A targeted GWAS was used to investigate whether ten candidate genes with known roles in corneal development were associated with CCT in two Singaporean populations. The single nucleotide polymorphisms (SNPs) within a 500 kb interval encompassing each candidate were analyzed, and in light of the resulting data, members of the Wnt pathway were subsequently screened using similar methodology.

    Results: Variants within the 500 kb interval encompassing three candidate genes, DKK1 (rs1896368, p=1.32×10-3), DKK2 (rs17510449, p=7.34×10-4), and FOXO1 (rs7326616, p=1.56×10-4 and rs4943785, p=1.19×10-3), were statistically significantly associated with CCT in the Singapore Indian population. DKK2 was statistically significantly associated with CCT in a separate Singapore Malaysian population (rs10015200, p=2.26×10-3). Analysis of Wnt signaling pathway genes in each population demonstrated that TCF7L2 (rs3814573, p=1.18×10-3), RYK (rs6763231, p=1.12×10-3 and rs4854785, p=1.11×10-3), and FZD8 (rs640827, p=5.17×10-4) were statistically significantly associated with CCT.

    Conclusions: The targeted GWAS identified four genes (DKK1, DKK2, RYK, and FZD8) with novel associations with CCT and confirmed known associations with two genes, FOXO1 and TCF7L2. All six participate in the Wnt pathway, supporting a broader role for Wnt signaling in regulating the thickness of the cornea. In parallel, this study demonstrated that a hypothesis-driven candidate gene approach can identify associations in existing GWAS data sets.

    Matched MeSH terms: Receptors, Cell Surface/genetics
  13. Ch'ng ES, Kumanogoh A
    Mol. Cancer, 2010;9:251.
    PMID: 20858260 DOI: 10.1186/1476-4598-9-251
    Sema4D, also known as CD100, is a protein belonging to class IV semaphorin. Its physiologic roles in the immune and nervous systems have been extensively explored. However, the roles of Sema4D have extended beyond these traditionally studied territories. Via interaction with its high affinity receptor Plexin-B1, Sema4D-Plexin-B1 involvement in tumor progression is strongly implied. Here, we critically review and delineate the Sema4D-Plexin-B1 interaction in many facets of tumor progression: tumor angiogenesis, regulation of tumor-associated macrophages and control of invasive growth. We correlate the in vitro and in vivo experimental data with the clinical study outcomes, and present a molecular mechanistic basis accounting for the intriguingly contradicting results from these recent studies.
    Matched MeSH terms: Receptors, Cell Surface/genetics; Receptors, Cell Surface/metabolism*
  14. Mohd-Lila MA, Yee LK, Cen LS, Bala JA, Balakrishnan KN, Allaudin ZN, et al.
    Microb Pathog, 2019 Sep;134:103572.
    PMID: 31163251 DOI: 10.1016/j.micpath.2019.103572
    The common physical and chemical methods for controlling rat pest are less than satisfactory and inhumane. Immunocontraception approach has been considered more humane and it can be accomplished by inducing the relevant host immune response that block further development of reproductive gametes. ZP3 proteins are known to play very important role during sperm-ovum fertilization. It is a self-antigen and only localized in female ovaries. Therefore, an immunization with ZP3 protein elsewhere will induce a generalize host immune response against ZP3 protein. This study employed rat ZP3 (rZP3) gene prepared from its cDNA of Rattus rattus diardii. It was delivered and expressed in vivo by naked plamid DNA (DrZP3) or recombinant ZP3-Adenovirus (Ad-rZP3). Expression studies in vitro with DrZP3 or Ad-ZP3 showed rZP3 proteins were successfully expressed in Vero cells. Hyperimmune serum against rZP3 that were prepared by immunizing several rats with purified rZP3-pichia yeast fusion protein showed it blocked sperms from binding DrZP3-transfected Vero cells. Female Sprague Dawley rats immunized with DrZP3 demonstrated a long-term effect for significant reduction of fertility up to 92.6%. Ovaries from rats immunized with DrZP3 were severely atrophied with disappearance of primordial follicles from ovarian cortex with an increased in the amount of oocyte-free cell clusters. Female rats immunized with Ad-rZP3 demonstrated 27% reduction of fertility. The infertility induced by Ad-rZP3 is comparatively low and ineffective. This could be due to a strong host immune response that suppresses the recombinant virus itself resulted in minimum rZP3 protein presentation to the host immune system. As a result, low antibody titers produced against rZP3 is insufficient to block oocytes from maturity and fertilization. Therefore, immunization with DrZP3 for immunocontraception is more effective than Ad-rZP3 recombinant adenovirus. It is proposed to explore further on the use of adenovirus or other alternative viruses to deliver ZP3 protein and for the development of enhanced expression of rZP3 in target host.
    Matched MeSH terms: Receptors, Cell Surface/genetics
  15. Yong YK, Shankar EM, Westhorpe CL, Maisa A, Spelman T, Kamarulzaman A, et al.
    Medicine (Baltimore), 2016 Aug;95(31):e4477.
    PMID: 27495090 DOI: 10.1097/MD.0000000000004477
    HIV-infected individuals on antiretroviral therapy (ART) are at increased risk of cardiovascular disease (CVD). Given the relationship between innate immune activation and CVD, we investigated the association of single-nucleotide polymorphisms (SNPs) in TLR4 and CD14 and carotid intima-media thickness (cIMT), a surrogate measurement for CVD, in HIV-infected individuals on ART and HIV-uninfected controls as a cross-sectional, case-control study. We quantified the frequency of monocyte subsets (CD14, CD16), markers of monocyte activation (CD38, HLA-DR), and endothelial adhesion (CCR2, CX3CR1, CD11b) by flow cytometry. Plasma levels of lipopolysaccharide, sCD163, sCD14, sCX3CL1, and sCCL2, were measured by ELISA. Genotyping of TLR4 and CD14 SNPs was also performed. The TT genotype for CD14/-260SNP but not the CC/CT genotype was associated with elevated plasma sCD14, and increased frequency of CD11b+CD14+ monocytes in HIV-infected individuals. The TT genotype was associated with lower cIMT in HIV-infected patients (n = 47) but not in HIV-uninfected controls (n = 37). The AG genotype for TLR4/+896 was associated with increased CX3CR1 expression on total monocytes among HIV-infected individuals and increased sCCL2 and fibrinogen levels in HIV-uninfected controls. SNPs in CD14/-260 and TLR4/+896 were significantly associated with different markers of systemic and monocyte activation and cIMT that differed between HIV-infected participants on ART and HIV-uninfected controls. Further investigation on the relationship of these SNPs with a clinical endpoint of CVD is warranted in HIV-infected patients on ART.
    Matched MeSH terms: Receptors, Cell Surface/blood
  16. Kue CS, Kamkaew A, Burgess K, Kiew LV, Chung LY, Lee HB
    Med Res Rev, 2016 Apr;36(3):494-575.
    PMID: 26992114 DOI: 10.1002/med.21387
    For the purpose of this review, active targeting in cancer research encompasses strategies wherein a ligand for a cell surface receptor expressed on tumor cells is used to deliver a cytotoxic or imaging cargo. This area of research is more than two decades old, but in those 20 and more years, how many receptors have been studied extensively? What kinds of the ligands are used for active targeting? Are they mostly naturally occurring molecules such as folic acid, or synthetic substances developed in campaigns for medicinal chemistry efforts? This review outlines the most important receptor or ligand combinations that have been used in active targeting to answer these questions, and therefore to address the most important one of all: is research in active targeting affording diminishing returns, or is this an area for which the potential far exceeds progress made so far?
    Matched MeSH terms: Receptors, Cell Surface
  17. Muh F, Lee SK, Hoque MR, Han JH, Park JH, Firdaus ER, et al.
    Malar J, 2018 Jul 27;17(1):272.
    PMID: 30049277 DOI: 10.1186/s12936-018-2420-4
    BACKGROUND: The rapid process of malaria erythrocyte invasion involves ligand-receptor interactions. Inducing antibodies against specific ligands or receptors that abrogate the invasion process is a key challenge for blood stage vaccine development. However, few candidates were reported and remain to be validated for the discovery of new vaccine candidates in Plasmodium knowlesi.

    METHODS: In order to investigate the efficacy of pre-clinical vaccine candidates in P. knowlesi-infected human cases, this study describes an in vitro invasion inhibition assay, using a P. knowlesi strain adapted to in vitro growth in human erythrocytes, PkA1-H.1. Recombinant proteins of P. knowlesi Duffy binding protein alpha (PkDBPα) and apical membrane antigen 1 (PkAMA1) were produced in Escherichia coli system and rabbit antibodies were generated from immune animals.

    RESULTS: PkDBPα and PkAMA1 recombinant proteins were expressed as insoluble and produced as a functional refolded form for this study. Antibodies against PkDBPα and PkAMA1 specifically recognized recombinant proteins and native parasite proteins in schizont-stage parasites on the merozoite organelles. Single and combination of anti-PkDBPα and anti-PkAMA1 antibodies elicited strong growth inhibitory effects on the parasite in concentration-dependent manner. Meanwhile, IgG prevalence of PkDBPα and PkAMA1 were observed in 13.0 and 46.7% in human clinical patients, respectively.

    CONCLUSION: These data provide support for the validation of in vitro growth inhibition assay using antibodies of DBPα and AMA1 in human-adapted P. knowlesi parasite PkA1-H.1 strain.

    Matched MeSH terms: Receptors, Cell Surface/immunology*
  18. Shao Y, Dang M, Lin Y, Xue F
    Life Sci, 2019 Aug 15;231:116422.
    PMID: 31059689 DOI: 10.1016/j.lfs.2019.04.048
    This study was performed to evaluate the antidiabetic and wound healing activity of plumbagin in diabetic rats by macroscopical, biochemical, histological, immunohistochemical and molecular methods. Percentage of wound closure and contraction was delayed in diabetic rats when compared to non-diabetic group. There was significant reduction in period of epithelialization, collagen and protein content. Serum insulin level was significantly lowered together with increase in glucose level in diabetic rats. Lipid levels were increased significantly with concomitant decrease in HDL level. The mRNA levels of Nrf2, collagen-1, TGF-β and α-SMA were significantly lowered whereas Keap-1 levels were increased in diabetic rats. The level of lipid peroxides was increased while the levels of antioxidants were lowered significantly. ELISA results reveal upregulated levels of inflammatory markers. Western blot result shows upregulated levels of CD68 and CD163 proteins in wound area of diabetic rats. Histopathological observation revealed increased inflammatory cells infiltration in diabetic control. Immunofluorescent staining and immunohistochemical analysis also displayed delayed wound healing in diabetic groups. Diabetic rats treated with 10% and 20% plumbagin showed increased epithelialization, collagen deposition, increased serum insulin level and increased antioxidant status. Lipid peroxides and lipid levels were lowered significantly with increase in HDL level. Inflammatory markers were lowered, and growth factors expressions were increased markedly. Thus, the results of the study indicated that plumbagin administration could improve wound healing activity and could serve as a potent antidiabetic and anti-inflammatory agent.
    Matched MeSH terms: Receptors, Cell Surface
  19. Alkaisi A, Ismail AR, Mutum SS, Ahmad ZA, Masudi S, Abd Razak NH
    J Oral Maxillofac Surg, 2013 Oct;71(10):1758.e1-13.
    PMID: 24040948 DOI: 10.1016/j.joms.2013.05.016
    The main aim of the present study was to evaluate the capacity of stem cells from human exfoliated deciduous teeth (SHED) to enhance mandibular distraction osteogenesis (DO) in rabbits.
    Matched MeSH terms: Receptors, Cell Surface/analysis
  20. Fong MY, Lau YL, Jelip J, Ooi CH, Cheong FW
    J Genet, 2019 Sep;98.
    PMID: 31544794
    Plasmodium knowlesi contributes to the majority of human malaria incidences in Malaysia. Its uncontrollable passage among the natural monkey hosts can potentially lead to zoonotic outbreaks. The merozoite of this parasite invades host erythrocytes through interaction between its erythrocyte-binding proteins (EBPs) and their respective receptor on the erythrocytes. The regionII of P. knowlesi EBP, P. knowlesi beta (PkβII) protein is found to be mediating merozoite invasion into monkey erythrocytes by interacting with sialic acid receptors. Hence, the objective of this study was to investigate the genetic diversity, natural selection and haplotype grouping of PkβII of P. knowlesi isolates in Malaysia. Polymerase chain reaction amplifications of PkβII were performed on archived blood samples from Malaysia and 64 PkβII sequences were obtained. Sequence analysis revealed length polymorphism, and its amino acids at critical residues indicate the ability of PkβII to mediate P. knowlesi invasion into monkey erythrocytes. Low genetic diversity (π = 0.007) was observed in the PkβII of Malaysia Borneo compared to Peninsular Malaysia (π = 0.015). The PkβII was found to be under strong purifying selection to retain infectivity in monkeys and it plays a limited role in the zoonotic potential of P. knowlesi. Its haplotypes could be clustered into Peninsular Malaysia and Malaysia Borneo groups, indicating the existence of two distinct P. knowlesi parasites in Malaysia as reported in an earlier study.
    Matched MeSH terms: Receptors, Cell Surface
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links