MyMedR

Displaying all 8 publications

Abstract:

Sort:

Preparation and characterization of cockle shell aragonite nanocomposite porous 3D scaffolds for bone repair

Mahmood SK, Zakaria MZAB, Razak ISBA, Yusof LM, Jaji AZ, Tijani I, et al.

Biochem Biophys Rep, 2017 Jul;10:237-251.
PMID: 28955752 DOI: 10.1016/j.bbrep.2017.04.008

The demands for applicable tissue-engineered scaffolds that can be used to repair load-bearing segmental bone defects (SBDs) is vital and in increasing demand. In this study, seven different combinations of 3 dimensional (3D) novel nanocomposite porous structured scaffolds were fabricated to rebuild SBDs using an extraordinary blend of cockle shells (CaCo3) nanoparticles (CCN), gelatin, dextran and dextrin to structure an ideal bone scaffold with adequate degradation rate using the Freeze Drying Method (FDM) and labeled as 5211, 5400, 6211, 6300, 7101, 7200 and 8100. The micron sized cockle shells powder obtained (75 µm) was made into nanoparticles using mechano-chemical, top-down method of nanoparticles synthesis with the presence of the surfactant BS-12 (dodecyl dimethyl bataine). The phase purity and crystallographic structures, the chemical functionality and the thermal characterization of the scaffolds' powder were recognized using X-Ray Diffractometer (XRD), Fourier transform infrared (FTIR) spectrophotometer and Differential Scanning Calorimetry (DSC) respectively. Characterizations of the scaffolds were assessed by Scanning Electron Microscopy (SEM), Degradation Manner, Water Absorption Test, Swelling Test, Mechanical Test and Porosity Test. Top-down method produced cockle shell nanoparticles having averagely range 37.8±3-55.2±9 nm in size, which were determined using Transmission Electron Microscope (TEM). A mainly aragonite form of calcium carbonate was identified in both XRD and FTIR for all scaffolds, while the melting (Tm) and transition (Tg) temperatures were identified using DSC with the range of Tm 62.4-75.5 °C and of Tg 230.6-232.5 °C. The newly prepared scaffolds were with the following characteristics: (i) good biocompatibility and biodegradability, (ii) appropriate surface chemistry and (iii) highly porous, with interconnected pore network. Engineering analyses showed that scaffold 5211 possessed 3D interconnected homogenous porous structure with a porosity of about 49%, pore sizes ranging from 8.97 to 337 µm, mechanical strength 20.3 MPa, Young's Modulus 271±63 MPa and enzymatic degradation rate 22.7 within 14 days.
Fulltext Relative proteome quantification of alpha, beta, gamma and delta globin chains in early eluting peaks of Bio-Rad variant II® CE-HPLC of hemoglobin from healthy and beta-thalassemia subjects in Malaysia

Abdullah UYH, Ibrahim HM, Jassim HM, Salleh MZ, Kek TL, Fakhruzzaman Bin Noorizhab MN, et al.

Biochem Biophys Rep, 2019 Jul;18:100635.
PMID: 31061897 DOI: 10.1016/j.bbrep.2019.100635

This is the first report of QQQ-mass spectrometric identification and quantification of the Hb subunits, alpha, beta, delta and gamma globin peptides, derived from enzymatic-digestion of proteins in the early unknown peaks of the Bio-Rad cation-exchange chromatography of haemoglobin. The objectives were to assess the relationship of the quantity of the free alpha, beta, delta and gamma globin chains with the phenotypic diversity of beta-thalassaemias (β-thal). The results demonstrate that the pools of free globin chains in red blood cells were correlating with the severity of the disease in patients with different phenotypes of β-thal. The mechanism and the regulation of synthesis of free globin chains pool in a normal individual and in patients with different β-thal phenotypes could arise from several mechanisms which will require further investigation. The role of the free globin pool in patients with β-thal for development of novel therapeutic approaches based on these potential targets requires further investigation. Pertinent biomarkers improves the diagnosis of the β-thal, especially in low-income countries where they are most common and allows more effective therapeutic intervention leading to more successful therapeutic outcome.
Fulltext Co-inhibition of BCL-XL and MCL-1 with selective BCL-2 family inhibitors enhances cytotoxicity of cervical cancer cell lines

Abdul Rahman SF, Muniandy K, Soo YK, Tiew EYH, Tan KX, Bates TE, et al.

Biochem Biophys Rep, 2020 Jul;22:100756.
PMID: 32346617 DOI: 10.1016/j.bbrep.2020.100756

Development of resistance to chemo- and radiotherapy in patients suffering from advanced cervical cancer narrows the therapeutic window for conventional therapies. Previously we reported that a combination of the selective BCL-2 family inhibitors ABT-263 and A-1210477 decreased cell proliferation in C33A, SiHa and CaSki human cervical cancer cell lines. As ABT-263 binds to both BCL-2 and BCL-XL with high affinity, it was unclear whether the synergism of the drug combination was driven either by singly inhibiting BCL-2 or BCL-XL, or inhibition of both. In this present study, we used the BCL-2 selective inhibitor ABT-199 and the BCL-XL selective inhibitor A1331852 to resolve the individual antitumor activities of ABT-263 into BCL-2 and BCL-XL dependent mechanisms. A-1210477 was substituted for the orally bioavailable S63845. Four cervical cancer cell lines were treated with the selective BCL-2 family inhibitors ABT-199, A1331852 and S63845 alone and in combination using 2-dimensional (2D) and 3-dimensional (3D) cell culture models. The SiHa, C33A and CaSki cell lines were resistant to single agent treatment of all three drugs, suggesting that none of the BCL-2 family of proteins mediate survival of the cells in isolation. HeLa cells were resistant to single agent treatment of ABT-199 and A1331852 but were sensitive to S63845 indicating that they depend on MCL-1 for survival. Co-inhibition of BCL-2 and MCL-1 with ABT-199 and S63845, inhibited cell proliferation of all cancer cell lines, except SiHa. However, the effect of the combination was not as pronounced as combination of A1331852 and S63845. Co-inhibition of BCL-XL and MCL-1 with A1331852 and S63845 significantly inhibited cell proliferation of all four cell lines. Similar data were obtained with 3-dimensional spheroid cell culture models generated from two cervical cancer cell lines in vitro. Treatment with a combination of A1331852 and S63845 resulted in inhibition of growth and invasion of the 3D spheroids. Collectively, our data demonstrate that the combination of MCL-1-selective inhibitors with either selective inhibitors of either BCL-XL or BCL-2 may be potentially useful as treatment strategies for the management of cervical cancer.
Fulltext Cloning and mutagenetic modification of the firefly luciferase gene and its use for bioluminescence microscopy of engrailed expression during Drosophila metamorphosis

Ogoh K, Akiyoshi R, Suzuki H

Biochem Biophys Rep, 2020 Sep;23:100771.
PMID: 32490216 DOI: 10.1016/j.bbrep.2020.100771

Bioluminescence microscopy is an area attracting considerable interest in the field of cell biology because it offers several advantages over fluorescence microscopy, including no requirement for excitation light and being phototoxicity free. This method requires brighter luciferase for imaging; however, suitable genetic resource material for this purpose is not available at present. To achieve brighter bioluminescence microscopy, we developed a new firefly luciferase. Using the brighter luciferase, a reporter strain of Drosophila Gal4-UAS (Upstream Activating Sequence) system was constructed. This system demonstrated the expression pattern of engrailed, which is a segment polarity gene, during Drosophila metamorphosis by bioluminescence microscopy, and revealed drastic spatiotemporal change in the engrailed expression pattern during head eversion in the early stage of pupation.
Fulltext The effect of α-tocopherol, α- and γ-tocotrienols on amyloid-β aggregation and disaggregation in vitro

Ibrahim NF, Hamezah HS, Yanagisawa D, Tsuji M, Kiuchi Y, Ono K, et al.

Biochem Biophys Rep, 2021 Dec;28:101131.
PMID: 34541343 DOI: 10.1016/j.bbrep.2021.101131

One of the neuropathological hallmarks of Alzheimer's disease (AD)-causing neurodegeneration and consequent memory deterioration, and eventually, cognitive decline-is amyloid-β (Aβ) aggregation forming amyloid plaques. Our previous study showed the potential of a tocotrienol-rich fraction-a mixture of naturally occurring of vitamin E analogs-to inhibit Aβ aggregation and restore cognitive function in an AD mouse model. The current study examined the effect of three vitamin E analogs-α-tocopherol (α-TOC), α-tocotrienol (α-T3), and γ-tocotrienol (γ-T3)-on Aβ aggregation, disaggregation, and oligomerization in vitro. Thioflavin T (ThT) assay showed α-T3 reduced Aβ aggregation at 10 μM concentration. Furthermore, both α-T3 and γ-T3 demonstrated Aβ disaggregation, as shown by the reduction of ThT fluorescence. However, α-TOC showed no significant effect. We confirmed the results for ThT assays with scanning electron microscopy imaging. Further investigation in photo-induced cross-linking of unmodified protein assay indicated a reduction in Aβ oligomerization by γ-T3. The present study thus revealed the individual effect of each tocotrienol analog in reducing Aβ aggregation and oligomerization as well as disaggregating preformed fibrils.
Fulltext Yeasts in sustainable bioethanol production: A review

Mohd Azhar SH, Abdulla R, Jambo SA, Marbawi H, Gansau JA, Mohd Faik AA, et al.

Biochem Biophys Rep, 2017 Jul;10:52-61.
PMID: 29114570 DOI: 10.1016/j.bbrep.2017.03.003

Bioethanol has been identified as the mostly used biofuel worldwide since it significantly contributes to the reduction of crude oil consumption and environmental pollution. It can be produced from various types of feedstocks such as sucrose, starch, lignocellulosic and algal biomass through fermentation process by microorganisms. Compared to other types of microoganisms, yeasts especially Saccharomyces cerevisiae is the common microbes employed in ethanol production due to its high ethanol productivity, high ethanol tolerance and ability of fermenting wide range of sugars. However, there are some challenges in yeast fermentation which inhibit ethanol production such as high temperature, high ethanol concentration and the ability to ferment pentose sugars. Various types of yeast strains have been used in fermentation for ethanol production including hybrid, recombinant and wild-type yeasts. Yeasts can directly ferment simple sugars into ethanol while other type of feedstocks must be converted to fermentable sugars before it can be fermented to ethanol. The common processes involves in ethanol production are pretreatment, hydrolysis and fermentation. Production of bioethanol during fermentation depends on several factors such as temperature, sugar concentration, pH, fermentation time, agitation rate, and inoculum size. The efficiency and productivity of ethanol can be enhanced by immobilizing the yeast cells. This review highlights the different types of yeast strains, fermentation process, factors affecting bioethanol production and immobilization of yeasts for better bioethanol production.
In vitro analysis of VEGF-mediated endothelial permeability and the potential therapeutic role of Anti-VEGF in severe dengue

Lim SJ, Gan SC, Ong HT, Ngeow YF

Biochem Biophys Rep, 2024 Sep;39:101814.
PMID: 39263317 DOI: 10.1016/j.bbrep.2024.101814

BACKGROUND: Vascular endothelial growth factor (VEGF) is one of the proteins involved in dengue immunopathogenesis. It is overexpressed in severe dengue and contributes to vascular permeability and plasma leakage. In this study, we investigated the effects of VEGF and anti-VEGF treatments on endothelial cells in vitro, to assess the potential use of anti-VEGF antibodies in managing severe dengue.
METHODS: Human pulmonary microvascular endothelial cells were treated with VEGF and a VEGF/anti-VEGF combination. The effects of the treatments were studied using an endothelial permeability assay and microarray gene expression profiling. In the permeability assay, the fluorescein isothiocyanate (FITC)-dextran fluorescence signal across the endothelial monolayer was recorded, and the cells were stained with PECAM-1 to detect gap formation. RNA was extracted from treated cells for microarray gene profiling and analysis. The results were analyzed for differentially expressed genes (DEGs) and gene enrichment analysis. The DEGs were subjected to STRING to construct the protein-protein interaction network and then Cytoscape to identify the hub genes.
RESULTS: VEGF-treated endothelial cells showed greater movement of FITC-dextran across the monolayer than VEGF/anti-VEGF-treated cells. There were 111 DEGs for VEGF-treated cells and 118 DEGs for VEGF/anti-VEGF-treated cells. The genes upregulated in VEGF-treated cells were enriched in inflammatory responses and regulation of the endothelial barrier, nitric oxide synthesis, angiogenesis, and the nucleotide-binding oligomerization domain-like receptor signaling pathway. Top 10 hub genes were identified from the DEGs.
CONCLUSIONS: VEGF treatment increased permeability across endothelial cells, while anti-VEGF reduced this leakage. Analysis of VEGF-treated endothelial cells identified hub genes implicated in severe dengue. The top 10 hub genes were TNF, IL1B, IL6, CCL2, PTGS2, ICAM1, CXCL2, CXCL1, CSF2, and TLR2. The results of this study show that using anti-VEGF antibodies to neutralize VEGF may be a promising therapy to prevent the progression of dengue to severe dengue.
Fulltext Renoprotective mechanisms of celastrol in high glucose-mediated HK-2 cell injury through inhibition of the PI3K/Akt/NF-κB signalling pathway

Wang X, Abu Bakar MH, Kassim MA, Shariff KA, Mohamad Rosdi MN

Biochem Biophys Rep, 2025 Mar;41:101928.
PMID: 39926209 DOI: 10.1016/j.bbrep.2025.101928

Hyperglycemia-induced inflammation and fibrosis in renal tubular epithelial cells are critical factors driving the progression of diabetic nephropathy (DN). Celastrol, a bioactive compound derived from Tripterygium wilfordii Hook.F, is recognized for its anti-inflammatory and anti-fibrotic properties. This study aimed to investigate the renoprotective effects of celastrol against high glucose (HG)-induced damage in human kidney 2 (HK-2) cells. Briefly, HK-2 cells were exposed to high glucose and treated with celastrol. Cell viability and apoptosis were evaluated using CCK-8 assay kit and flow cytometry, respectively. The pro-inflammatory cytokines, oxidative stress markers, and fibrotic-related proteins were measured using ELISA and immunoblotting. To further confirm the mechanistic actions of celastrol, the PI3K/Akt/NF-κB pathway was examined, and HG-treated cells were co-incubated with the NF-κB inhibitor bortezomib. Our result revealed that celastrol at the moderate concentration of 50 nM mitigated HG-induced toxicity, suggesting an optimal therapeutic window. Celastrol improved cell viability and reduced apoptosis in HG-treated HK-2 cells. It significantly decreased levels of inflammatory cytokines such as IL-6, TNF-α, IL-1β, and MCP-1, while enhancing antioxidant activities of GSH-Px and SOD, and lowering MDA levels, indicating diminished oxidative stress. Mechanistically, these renoprotective effects of celastrol partly attributed via inhibition of the PI3K/Akt/NF-κB signalling pathway, as blocking NF-κB signalling by bortezomib resulted in similar inhibitory effects against inflammation and fibrosis. Collectively, celastrol acts as a renoprotective agent against renal inflammation, oxidative stress, and fibrosis, partly through the inhibition of the PI3K/Akt/NF-κB pathway, offering potential therapeutic benefits against hyperglycemia-induced renal injury in DN.