Displaying publications 21 - 40 of 55 in total

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  1. Abd Ghafar N, Chua KH, Wan Ngah WZ, Che Hamzah J, Othman F, Abd Rahman R, et al.
    Cell Tissue Bank, 2014 Mar;15(1):25-34.
    PMID: 23292197 DOI: 10.1007/s10561-012-9360-y
    The in vivo quiescent corneal stroma keratocytes need to be transformed to activated state in order to obtain sufficient number of cells either for monolayer evaluation or corneal stroma reconstruction. This study aimed to investigate the phenotypic characterization of corneal stromal cells during culture expansion from the limbal region of the cornea. Isolated corneal keratocytes from limbal tissue of New Zealand White Strain rabbits' corneas (n = 6) were culture expanded until three passages. Keratocytes morphology was examined daily with viability, growth rate, number of cell doubling and population doubling time were recorded at each passage. The expression of collagen type 1, aldehyde dehydrogenase (ALDH), lumican and alpha smooth muscle actin (α-SMA) were detected by RT-PCR. Immunocytochemistry was also used to detect ALDH, α-SMA, collagen type I and Cytokeratin-3 (CK3). Growth kinetic study revealed that the growth rate was low at the initial passage but increase to about two folds with concomitant reduction in population doubling time in later passages. Freshly isolated and cultured keratocytes expressed collagen type 1, ALDH and lumican but α-SMA expression was absent. However, α-SMA was expressed along with the other genes during culture expansion. Keratocytes at P1 expressed all the proteins except CK3. These results suggest that cultured keratocytes maintained most of the gene expression profile of native keratocytes while the emergence of α-SMA in serial passages showed a mix population of various phenotypes. The phenotypic characterization of monolayer keratocytes provides useful information before reconstruction of bioengineered tissue or in vitro pharmaceutical applications.
    Matched MeSH terms: Collagen Type I/biosynthesis
  2. Mohamad N, Loh EYX, Fauzi MB, Ng MH, Mohd Amin MCI
    Drug Deliv Transl Res, 2019 04;9(2):444-452.
    PMID: 29302918 DOI: 10.1007/s13346-017-0475-3
    The healing of wounds, including those from burns, currently exerts a burden on healthcare systems worldwide. Hydrogels are widely used as wound dressings and in the field of tissue engineering. The popularity of bacterial cellulose-based hydrogels has increased owing to their biocompatibility. Previous study demonstrated that bacterial cellulose/acrylic acid (BC/AA) hydrogel increased the healing rate of burn wound. This in vivo study using athymic mice has extended the use of BC/AA hydrogel by the addition of human epidermal keratinocytes and human dermal fibroblasts. The results showed that hydrogel loaded with cells produces the greatest acceleration on burn wound healing, followed by treatment with hydrogel alone, compared with the untreated group. The percentage wound reduction on day 13 in the mice treated with hydrogel loaded with cells (77.34 ± 6.21%) was significantly higher than that in the control-treated mice (64.79 ± 6.84%). Histological analysis, the expression of collagen type I via immunohistochemistry, and transmission electron microscopy indicated a greater deposition of collagen in the mice treated with hydrogel loaded with cells than in the mice administered other treatments. Therefore, the BC/AA hydrogel has promising application as a wound dressing and a cell carrier.
    Matched MeSH terms: Collagen Type I/metabolism
  3. Daood U, Abduljabbar T, Al-Hamoudi N, Akram Z
    J Periodontal Res, 2018 Feb;53(1):123-130.
    PMID: 28940417 DOI: 10.1111/jre.12496
    BACKGROUND AND OBJECTIVE: The aim of the present study was to compare clinical periodontal parameters and to assess the release of C-telopeptides pyridinoline cross-links (ICTP) and C-terminal crosslinked telopeptide (CTX) from gingival collagen of naswar (NW) and non-naswar (control) dippers.

    MATERIAL AND METHODS: Eighty-seven individuals (42 individuals consuming NW and 45 controls) were included. Clinical (plaque index, bleeding on probing, probing depth and clinical attachment loss) and radiographic (marginal bone loss) periodontal parameters were compared among NW and control groups. Gingival specimens were taken from subjects in NW and control groups, assessed for ICTP and CTX levels (using ELISA) and analyzed using micro-Raman spectroscopy. The significance of differences in periodontal parameters between the groups was determined using Kruskal-Wallis and Mann-Whitney U tests. The percent loss of dry mass over exposure time and the rate of release of ICTP and CTX from all groups were compared using the paired t-test to examine the effects of exposure time.

    RESULTS: Clinical and radiographic periodontal parameters were significantly higher in the NW group than the control group (P I was observed with slight shifts in wave numbers. The rate of ICTP and CTX release was significantly higher in subjects from the NW group compared with those from the control group (P type of groups and time, had a significant effect on release of ICTP and CTX (P collagen breakdown in the connective tissue of subjects in the NW group as a result of naswar usage.

    Matched MeSH terms: Collagen Type I/metabolism*
  4. Md Noh SM, Sheikh Abdul Kadir SH, Bannur ZM, Froemming GA, Abdul Hamid Hasani N, Mohd Nawawi H, et al.
    Exp Eye Res, 2014 Oct;127:236-42.
    PMID: 25139730 DOI: 10.1016/j.exer.2014.08.005
    Anti-Vascular Endothelial Growth Factors (Anti-VEGF) agents have received recent interest as potential anti-fibrotic agents for their concurrent use with trabeculectomy. Preliminary cohort studies have revealed improved bleb morphology following trabeculectomy augmented with ranibizumab. The effects of this humanized monoclonal antibody on human Tenon's fibroblast (HTF), the key player of post trabeculectomy scar formation, are not fully understood. This study was conducted to understand the effects of ranibizumab on extracellular matrix production by HTF. The effect of ranibizumab on HTF proliferation and cell viability was determined using MTT assay (3-(4,5-dimethylthiazone-2-yl)-2,5-diphenyl tetrazolium). Ranibizumab at concentrations ranging from 0.01 to 0.5 mg/mL were administered for 24, 48 and 72 h in serum and serum free conditions. Supernatants and cell lysates from samples were assessed for collagen type 1 alpha 1 and fibronectin mRNA and protein level using quantitative real time polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA). After 48-h, ranibizumab at 0.5 mg/mL, significantly induced cell death under serum-free culture conditions (p collagen type 1 alpha 1 (COL1A1) mRNA, but not for fibronectin (FN). Meanwhile, COL1A1 and FN protein levels were found upregulated in treated monolayers compared to control monolayers. Ranibizumab at 0.5 mg/mL significantly reduced cell viability in cultured HTF. From this study, we found that single application of ranibizumab is inadequate to induce the anti-fibrotic effects on HTF, suggesting the importance of adjunctive therapy. Further studies are underway to understand mechanism of actions of ranibizumab on HTF.
    Matched MeSH terms: Collagen Type I/genetics*; Collagen Type I/metabolism
  5. Wan Hasan WN, Abd Ghafar N, Chin KY, Ima-Nirwana S
    Drug Des Devel Ther, 2018;12:1715-1726.
    PMID: 29942115 DOI: 10.2147/DDDT.S168935
    PURPOSE: Annatto-derived tocotrienol (AnTT) has been shown to improve bone formation in animal models of osteoporosis. However, detailed studies of the effects of AnTT on preosteoblastic cells were limited. This study was conducted to investigate the osteogenic effect of AnTT on preosteoblast MC3T3-E1 cells in a time-dependent manner.

    MATERIALS AND METHODS: Murine MC3T3-E1 preosteoblastic cells were cultured in the different concentrations of AnTT (0.001-1 µg/mL) up to 24 days. Expression of osteoblastic differentiation markers was measured by qPCR (osterix [OSX], collagen 1 alpha 1 [COL1α1], alkaline phosphatase [ALP], and osteocalcin [OCN]) and by fluorometric assay for ALP activity. Detection of collagen and mineralized nodules was done via Direct Red staining and Alizarin Red staining, respectively.

    RESULTS: The results showed that osteoblastic differentiation-related genes, such as OSX, COL1α1, ALP, and OCN, were significantly increased in the AnTT-treated groups compared to the vehicle group in a time-dependent manner (P<0.05). Type 1 collagen level was increased from day 3 to day 15 in the AnTT-treated groups, while ALP activity was increased from day 9 to day 21 in the AnTT-treated groups (P<0.05). Enhanced mineralization was observed in the AnTT-treated groups via increasing Alizarin Red staining from day 3 to day 21 (P<0.05).

    CONCLUSION: Our results suggest that AnTT enhances the osteogenic activity by promoting the bone formation-related genes and proteins in a temporal and sequential manner.

    Matched MeSH terms: Collagen Type I/genetics; Collagen Type I/metabolism
  6. Makpol S, Zainuddin A, Chua KH, Yusof YA, Ngah WZ
    Clinics (Sao Paulo), 2012;67(2):135-43.
    PMID: 22358238
    OBJECTIVE: Human diploid fibroblasts undergo a limited number of cellular divisions in culture and progressively reach a state of irreversible growth arrest, a process termed cellular aging. The beneficial effects of vitamin E in aging have been established, but studies to determine the mechanisms of these effects are ongoing. This study determined the molecular mechanism of γ-tocotrienol, a vitamin E homolog, in the prevention of cellular aging in human diploid fibroblasts using the expression of senescence-associated genes.

    METHODS: Primary cultures of young, pre-senescent, and senescent fibroblast cells were incubated with γ-tocotrienol for 24 h. The expression levels of ELN, COL1A1, MMP1, CCND1, RB1, and IL6 genes were determined using the quantitative real-time polymerase chain reaction. Cell cycle profiles were determined using a FACSCalibur Flow Cytometer.

    RESULTS: The cell cycle was arrested in the G(0)/G(1) phase, and the percentage of cells in S phase decreased with senescence. CCND1, RB1, MMP1, and IL6 were upregulated in senescent fibroblasts. A similar upregulation was not observed in young cells. Incubation with γ-tocotrienol decreased CCND1 and RB1 expression in senescent fibroblasts, decreased cell populations in the G(0)/G(1) phase and increased cell populations in the G(2)/M phase. γ-Tocotrienol treatment also upregulated ELN and COL1A1 and downregulated MMP1 and IL6 expression in young and senescent fibroblasts.

    CONCLUSION: γ-Tocotrienol prevented cellular aging in human diploid fibroblasts, which was indicated by the modulation of the cell cycle profile and senescence-associated gene expression.

    Matched MeSH terms: Collagen Type I/genetics; Collagen Type I/metabolism
  7. Chin KY, Ima-Nirwana S
    Clin Interv Aging, 2014;9:1247-59.
    PMID: 25120355 DOI: 10.2147/CIA.S67016
    BACKGROUND: Previous animal models have demonstrated that tocotrienol is a potential treatment for postmenopausal osteoporosis. This study evaluated the antiosteoporotic effects of annatto-derived tocotrienol (AnTT) using a testosterone-deficient osteoporotic rat model.
    METHODS: Forty rats were divided randomly into baseline, sham, orchidectomized, AnTT, and testosterone groups. The baseline group was euthanized without undergoing any surgical treatment or intervention. The remaining groups underwent orchidectomy, with the exception of the sham group. AnTT 60 mg/kg/day was given orally to the AnTT group, while the testosterone group received testosterone enanthate 7 mg/kg per week intramuscularly for 8 weeks. Structural changes in trabecular bone at the proximal tibia were examined using microcomputed tomography. Structural and dynamic changes at the distal femur were examined using histomorphometric methods. Serum osteocalcin and C-terminal of type 1 collagen crosslinks were measured. Bone-related gene expression in the distal femur was examined.
    RESULTS: There were significant degenerative changes in structural indices in the orchidectomized group (P<0.05), but no significant changes in dynamic indices, bone remodeling markers, or gene expression (P>0.05) when compared with the sham group. The AnTT group showed significant improvement in structural indices at the femur (P<0.05) and significantly increased expression of bone formation genes (P<0.05). Testosterone was more effective than AnTT in preventing degeneration of bone structural indices in the femur and tibia (P<0.05).
    CONCLUSION: AnTT supplementation improves bone health in testosterone-deficient rats by enhancing bone formation. Its potential should be evaluated further by varying the dosage and treatment duration.
    KEYWORDS: bone remodeling; osteoporosis; testosterone; tocotrienol
    Matched MeSH terms: Collagen Type I/blood
  8. Helali AM, Iti FM, Mohamed IN
    Curr Drug Targets, 2013 Dec;14(13):1591-600.
    PMID: 23957815
    Osteoporosis is a pathologic process characterized by low bone mass with skeletal fragility and an increased risk of fracture. It occurs due to an imbalance between bone resorption and formation. Although current antiresorptive therapy halts bone loss, it does not cure the condition as it also inhibits bone formation. Recent preclinical and clinical trials suggest that the inhibition of resorption by cathepsin K inhibitors increases bone formation. Cathepsin K is a papainlike cysteine protease with high potent collagenase activity and predominantly expressed in osteoclasts. While allowing demineralization, cathepsin K inhibitors suppress the degradation of type I collagen (the major organic matrix of bone) and thus enhancing bone formation. Many of these inhibitors have passed preclinical studies and are presently in clinical trials at different stages of advancement. This review explores the promising role of cathepsin K as a novel antiresorptive for the treatment of osteoporosis.
    Matched MeSH terms: Collagen Type I/metabolism
  9. Shuid AN, Abu Bakar MF, Abdul Shukor TA, Muhammad N, Mohamed N, Soelaiman IN
    Aging Male, 2011 Sep;14(3):150-4.
    PMID: 20874437 DOI: 10.3109/13685538.2010.511327
    Osteoporosis in elderly men is becoming an important health issue with the aging society. Elderly men with androgen deficiency are exposed to osteoporosis and can be treated with testosterone replacement. In this study, Eurycoma longifolia (EL), a plant with androgenic effects, was supplemented to an androgen-deficient osteoporotic aged rat as alternative to testosterone. Aged 12 months old Sprague-Dawley rats were divided into groups of normal control (NC), sham-operated (SO), orchidectomised-control (OrxC), orchidectomised and supplemented with EL (Orx + El) and orchidectomised and given testosterone (Orx + T). After 6 weeks of treatment, serum osteocalcin, serum terminal C-telopeptide Type 1 collagen (CTX) and the fourth lumbar bone calcium were measured. There were no significant differences in the osteocalcin levels before and after treatment in all the groups. The CTX levels were also similar for all the groups before treatment. However, after treatment, orchidectomy had caused significant elevation of CTX compared to normal control rats. Testosterone replacements in orchidectomised rats were able to prevent the rise of CTX. Orchidectomy had also reduced the bone calcium level compared to normal control rats. Both testosterone replacement and EL supplementation to orchidectomised rats were able to maintain the bone calcium level, with the former showing better effects. As a conclusion, EL prevented bone calcium loss in orchidectomised rats and therefore has the potential to be used as an alternative treatment for androgen deficient osteoporosis.
    Matched MeSH terms: Collagen Type I/blood
  10. Farah Wahida I, Aminuddin BS, Munirah S, Chua KH, Fuzina NH, Isa MR, et al.
    Med J Malaysia, 2004 May;59 Suppl B:190-1.
    PMID: 15468882
    This study was to assess collagen type II and collagen type I gene expression in tissue-engineered human auricular: cartilage formed via tissue engineering technique. Large-scale culture expansions were transformed into 3D in vitro construct and were implanted subcutaneously on the dorsal of athymic mice. After 8 weeks, explanted construct was processed in the same manner of native cartilage to facilitate cells for gene expression analysis. Isolated cells from in vivo construct demonstrated expression of type II collagen gene comparable to native cartilage. This study verified that tissue-engineered auricular cartilage expressed cartilage specific gene, collagen type II after in vivo maturation.
    Matched MeSH terms: Collagen Type I/genetics*; Collagen Type II/genetics*
  11. Chua KH, Aminuddin BS, Fuzina NH, Ruszymah BH
    Med J Malaysia, 2004 May;59 Suppl B:194-5.
    PMID: 15468884
    We have previously formulated an optimized human chondrocytes growth medium based on 2% fetal bovine serum supplementation. For clinical usage, the animal serum must be replaced by patient own serum. We investigated the effects of human serum concentration for human nasal septum chondrocytes monolayer culture and cartilage reconstruction. Human serum demonstrated a dose dependent manner in promoting chondrocytes growth and cartilage engineering.
    Matched MeSH terms: Collagen Type I/genetics; Collagen Type II/genetics
  12. Manira M, Khairul Anuar K, Seet WT, Ahmad Irfan AW, Ng MH, Chua KH, et al.
    Cell Tissue Bank, 2014 Mar;15(1):41-9.
    PMID: 23456438 DOI: 10.1007/s10561-013-9368-y
    Animal-derivative free reagents are preferred in skin cell culture for clinical applications. The aim of this study was to compare the performance and effects between animal-derived trypsin and recombinant trypsin for skin cells culture and expansion. Full thickness human skin was digested in 0.6 % collagenase for 6 h to liberate the fibroblasts, followed by treatment with either animal-derived trypsin; Trypsin EDTA (TE) or recombinant trypsin; TrypLE Select (TS) to liberate the keratinocytes. Both keratinocytes and fibroblasts were then culture-expanded until passage 2. Trypsinization for both cell types during culture-expansion was performed using either TE or TS. Total cells yield was determined using a haemocytometer. Expression of collagen type I, collagen type III (Col-III), cytokeratin 10, and cytokeratin 14 genes were quantified via RT-PCR and further confirmed with immunocytochemical staining. The results of our study showed that the total cell yield for both keratinocytes and fibroblasts treated with TE or TS were comparable. RT-PCR showed that expression of skin-specific genes except Col-III was higher in the TS treated group compared to that in the TE group. Expression of proteins specific to the two cell types were confirmed by immunocytochemical staining in both TE and TS groups. In conclusion, the performance of the recombinant trypsin is comparable with the well-established animal-derived trypsin for human skin cell culture expansion in terms of cell yield and expression of specific cellular markers.
    Matched MeSH terms: Collagen Type I/biosynthesis; Collagen Type III/biosynthesis
  13. Chua KH, Aminuddin BS, Fuzina NH, Ruszymah BH
    Eur Cell Mater, 2005 Jun 17;9:58-67; discussion 67.
    PMID: 15962238
    This study was to investigate the effects of insulin-transferrin-selenium (ITS) on the proliferation and quantitative gene expression of adult human nasal septum chondrocytes in monolayer culture expansion and the formation of tissue engineered hyaline cartilage. Effects of ITS on human nasal septum chondrocytes monolayer culture expansion and gene expression were evaluated in various culture media either added with 2% fetal bovine serum (FBS) or 1 ng/mL basic fibroblast growth factor plus 1 ng/mL transforming growth factor or both serum and growth factors supplementation in comparison with medium added with 10%FBS. Chondrocytes cultured in medium added with 2% fetal bovine serum and growth factors either supplemented with or without ITS were then mixed with pluronic F-127 hydrogel for in vivo tissue engineered cartilage formation in nude mice model. Engineered tissues were removed after 8 weeks of implantation and evaluated with histological staining, immunohistochemistry, transmission electron microscopy and quantitative gene expression analysis. ITS promoted human chondrocytes proliferation and reduced chondrocytes dedifferentiation in media supplemented with serum and growth factors. ITS with 2% FBS and growth factors provided 15-fold increased in chondrocytes number by the end of the culture period compared to the standard culture medium used in chondrocytes culture (medium added with 10% FBS). Engineered tissue resulted from ITS supplementation demonstrated higher quality of cartilage formation. In conclusion, our study has demonstrated the benefits of ITS supplementation in human chondrocytes monolayer culture and tissue engineering cartilage formation.
    Matched MeSH terms: Collagen Type I/genetics; Collagen Type II/genetics
  14. Tan KM, Saw S, Sethi SK
    J Clin Lab Anal, 2013 Jul;27(4):301-4.
    PMID: 23852789 DOI: 10.1002/jcla.21602
    BACKGROUND: In this study, we aimed to determine the normal ranges of 25-hydroxy-vitamin D(3) (25-OHD(3)), parathyroid hormone (PTH), and the markers of bone turnover, procollagen type 1 N propeptide (P1NP) and C-terminal cross-linked telopeptide of type 1 collagen (CTX), in normal healthy women in Singapore, and to explore the relationship between vitamin D, PTH, and these markers of bone turnover in the women.

    METHODS: One hundred and ninety-seven healthy women, aged 25 to 60, were selected from a hospital staff health screening program; 68% were Chinese, 18% Malay, and 14% Indian. P1NP, CTX, and 25-OHD(3) were measured using the Roche Cobas® electrochemiluminescence immunoassay. Serum PTH was measured using the Siemens ADVIA Centaur® immunoassay.

    RESULTS: Sixty-five percent had 25-OHD(3) concentrations <50 nmol/l. Vitamin D insufficiency (25-OHD(3) < 50 nmol/l) was more prevalent in Malays (89%) and Indians (82%) compared to Chinese (56%). There was no correlation between vitamin D and age. PTH positively correlated with age, and Malays and Indians had higher PTH concentrations than Chinese. There was an inverse correlation between PTH and 25-OHD(3), but no threshold of 25-OHD(3) concentrations at which PTH plateaued. The bone turnover markers P1NP and CTX inversely correlated with age but were not different between ethnic groups. CTX and P1NP exhibited good correlation, however, there was no significant correlation between 25-OHD(3) or PTH concentrations and the bone turnover markers P1NP and CTX.

    CONCLUSIONS: Healthy women in Singapore have a high prevalence of vitamin D insufficiency. Vitamin D insufficiency was more prevalent in Malays and Indians compared to Chinese.

    Matched MeSH terms: Collagen Type I/blood
  15. Akhir HM, Teoh PL
    Biosci Rep, 2020 12 23;40(12).
    PMID: 33245097 DOI: 10.1042/BSR20201325
    Collagen has been widely shown to promote osteogenesis of bone marrow mesenchymal stromal cells (BM-MSCs). Due to the invasive procedure of obtaining BM-MSCs, MSCs from other tissues have emerged as a promising alternative for regenerative therapy. MSCs originated from different sources, exhibiting different differentiation potentials. Therefore, the applicability of collagen type I (COL), combining with amniotic membrane (AM)-MSCs was examined through proliferation and differentiation assays together with the expression of surface markers and genes associated with stemness and differentiation under basal or induction conditions. No increase in cell growth was observed because AM-MSCs might be directed toward spontaneous osteogenesis. This was evidenced by the calcium deposition and elevated expression of osteogenic genes when AM-MSCs were cultured in collagen plate with basal media. Under the osteogenic condition, reciprocal expression of OCN and CEBPA suggested a shift toward adipogenesis. Surprisingly, adipogenic genes were not elevated upon adipogenic induction, although oil droplets deposition was observed. In conclusion, our findings demonstrated that collagen causes spontaneous osteogenesis in AM-MSCs. However, the presence of exogenous inductors could shift the direction of adipo-osteogenic gene regulatory network modulated by collagen.
    Matched MeSH terms: Collagen Type I/pharmacology*
  16. Kruger MC, Chan YM, Lau LT, Lau CC, Chin YS, Kuhn-Sherlock B, et al.
    Eur J Nutr, 2018 Dec;57(8):2785-2794.
    PMID: 28975432 DOI: 10.1007/s00394-017-1544-6
    PURPOSE: In Malaysia, hip fracture incidence is higher in Chinese women than other ethnic groups. This study compared the effects of a high-calcium vitamin D fortified milk with added FOS-inulin versus regular milk over 1 year on aspects of bone health in Chinese postmenopausal women in Malaysia.

    METHODS: One-hundred and twenty-one women (mean age 59 (± 4) years) were randomized into two groups: control (n = 60; regular milk, 428 mg calcium per day) or intervention (n = 61; fortified milk at 1200 mg calcium, 96 mg magnesium, 2.4 mg zinc, 15 μg vitamin D and 4 g FOS-inulin per day). At baseline, weeks 12, 24, 36 and 52, parathyroid hormone (PTH), C-Telopeptide of Type I Collagen (CTx-1), Procollagen I Intact N-Terminal propeptide (PINP) and vitamin D levels were assessed. Bone density (BMD) was measured at baseline and week 52 using a GE Lunar iDXA.

    RESULTS: Body mass index, lumbar spine and femoral neck BMD did not differ between groups at baseline. Over 52 weeks, mean plasma 25 (OH) D3 levels increased to 74.8 nmol/L (intervention group) or remained at 63.1 nmol/L (control group) (p 

    Matched MeSH terms: Collagen Type I/blood
  17. Raghavendran HR, Mohan S, Genasan K, Murali MR, Naveen SV, Talebian S, et al.
    Colloids Surf B Biointerfaces, 2016 Mar 1;139:68-78.
    PMID: 26700235 DOI: 10.1016/j.colsurfb.2015.11.053
    Scaffolds with structural features similar to the extracellular matrix stimulate rapid osteogenic differentiation in favorable microenvironment and with growth factor supplementation. In this study, the osteogenic potential of electrospun poly-l-lactide/hydroxyapatite/collagen (PLLA/Col/HA, PLLA/HA and PLLA/Col) scaffolds were tested in vitro with the supplementation of platelet derived growth factor-BB (PDGF-BB). Cell attachment and topography, mineralization, extracellular matrix protein localization, and gene expression of the human mesenchymal stromal cells were compared between the fibrous scaffolds PLLA/Col/HA, PLLA/Col, and PLLA/HA. The levels of osteocalcin, calcium, and mineralization were significantly greater in the PLLA/Col/HA and PLLA/HA compared with PLLA/Col. High expression of fibronectin, intracellular adhesion molecule, cadherin, and collagen 1 (Col1) suggests that PLLA/Col/HA and PLLA/HA scaffolds had superior osteoinductivity than PLLA/Col. Additionally, osteopontin, osteocalcin, osterix, Runt-related transcription factor 2 (Runx2), and bone morphogenic protein (BMP2) expression were higher in PLLA/Col/HA and PLLA/HA compared with PLLA/Col. In comparison with PLLA/Col, the PLLA/Col/HA and PLLA/HA scaffolds presented a significant upregulation of the genes Runx2, Col 1, Integrin, osteonectin (ON), bone gamma-carboxyglutamic acid-containing protein (BGALP), osteopontin (OPN), and BMP2. The upregulation of these genes was further increased with PDGF-BB supplementation. These results show that PDGF-BB acts synergistically with PLLA/Col/HA and PLLA/HA to enhance the osteogenic differentiation potential. Therefore, this combination can be used for the rapid expansion of bone marrow stromal cells into bone-forming cells for tissue engineering.
    Matched MeSH terms: Collagen Type I/genetics; Collagen Type I/metabolism; Collagen Type I/pharmacology*
  18. Siew Ching H, Thirumulu Ponnuraj K, Luddin N, Ab Rahman I, Nik Abdul Ghani NR
    Polymers (Basel), 2020 Sep 17;12(9).
    PMID: 32957636 DOI: 10.3390/polym12092125
    This study aimed to investigate the effects of nanohydroxyapatite-silica-glass ionomer cement (nanoHA-silica-GIC) on the differentiation of dental pulp stem cells (DPSCs) into odontogenic lineage. DPSCs were cultured in complete Minimum Essential Medium Eagle-Alpha Modification (α-MEM) with or without nanoHA-silica-GIC extract and conventional glass ionomer cement (cGIC) extract. Odontogenic differentiation of DPSCs was evaluated by real-time reverse transcription polymerase chain reaction (rRT-PCR) for odontogenic markers: dentin sialophosphoprotein (DSPP), dentin matrix protein 1 (DMP1), osteocalcin (OCN), osteopontin (OPN), alkaline phosphatase (ALP), collagen type I (COL1A1), and runt-related transcription factor 2 (RUNX2) on day 1, 7, 10, 14, and 21, which were normalized to the house keeping gene glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Untreated DPSCs were used as a control throughout the study. The expressions of DSPP and DMP1 were higher on days 7 and 10, that of OCN on day 10, those of OPN and ALP on day 14, and that of RUNX2 on day 1; COL1A1 exhibited a time-dependent increase from day 7 to day 14. Despite the above time-dependent variations, the expressions were comparable at a concentration of 6.25 mg/mL between the nanoHA-silica-GIC and cGIC groups. This offers empirical support that nanoHA-silica-GIC plays a role in the odontogenic differentiation of DPSCs.
    Matched MeSH terms: Collagen Type I
  19. Boyle ST, Mittal P, Kaur G, Hoffmann P, Samuel MS, Klingler-Hoffmann M
    J Proteome Res, 2020 10 02;19(10):4093-4103.
    PMID: 32870688 DOI: 10.1021/acs.jproteome.0c00511
    Tumorigenesis involves a complex interplay between genetically modified cancer cells and their adjacent normal tissue, the stroma. We used an established breast cancer mouse model to investigate this inter-relationship. Conditional activation of Rho-associated protein kinase (ROCK) in a model of mammary tumorigenesis enhances tumor growth and progression by educating the stroma and enhancing the production and remodeling of the extracellular matrix. We used peptide matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) to quantify the proteomic changes occurring within tumors and their stroma in their regular spatial context. Peptides were ranked according to their ability to discriminate between the two groups, using a receiver operating characteristic tool. Peptides were identified by liquid chromatography tandem mass spectrometry, and protein expression was validated by quantitative immunofluorescence using an independent set of tumor samples. We have identified and validated four key proteins upregulated in ROCK-activated mammary tumors relative to those expressing kinase-dead ROCK, namely, collagen I, α-SMA, Rab14, and tubulin-β4. Rab14 and tubulin-β4 are expressed within tumor cells, whereas collagen I is localized within the stroma. α-SMA is predominantly localized within the stroma but is also expressed at higher levels in the epithelia of ROCK-activated tumors. High expression of COL1A, the gene encoding the pro-α 1 chain of collagen, correlates with cancer progression in two human breast cancer genomic data sets, and high expression of COL1A and ACTA2 (the gene encoding α-SMA) are associated with a low survival probability (COLIA, p = 0.00013; ACTA2, p = 0.0076) in estrogen receptor-negative breast cancer patients. To investigate whether ROCK-activated tumor cells cause stromal cancer-associated fibroblasts (CAFs) to upregulate expression of collagen I and α-SMA, we treated CAFs with medium conditioned by primary mammary tumor cells in which ROCK had been activated. This led to abundant production of both proteins in CAFs, clearly highlighting the inter-relationship between tumor cells and CAFs and identifying CAFs as the potential source of high levels of collagen 1 and α-SMA and associated enhancement of tissue stiffness. Our research emphasizes the capacity of MALDI-MSI to quantitatively assess tumor-stroma inter-relationships and to identify potential prognostic factors for cancer progression in human patients, using sophisticated mouse cancer models.
    Matched MeSH terms: Collagen Type I
  20. Tan HY, Tan SL, Teo SH, Roebuck MM, Frostick SP, Kamarul T
    PeerJ, 2020;8:e8740.
    PMID: 32587790 DOI: 10.7717/peerj.8740
    Background: Type 2 diabetes mellitus (T2DM) had been reported to be associated with tendinopathy. However, the underlying mechanisms of diabetic tendinopathy still remain largely to be discovered. The purpose of this study was to develop insulin resistance (IR) model on primary human tenocytes (hTeno) culture with tumour necrosis factor-alpha (TNF-α) treatment to study tenocytes homeostasis as an implication for diabetic tendinopathy.

    Methods: hTenowere isolated from human hamstring tendon. Presence of insulin receptor beta (INSR-β) on normal tendon tissues and the hTeno monolayer culture were analyzed by immunofluorescence staining. The presence of Glucose Transporter Type 1 (GLUT1) and Glucose Transporter Type 4 (GLUT4) on the hTeno monolayer culture were also analyzed by immunofluorescence staining. Primary hTeno were treated with 0.008, 0.08, 0.8 and 8.0 µM of TNF-α, with and without insulin supplement. Outcome measures include 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-d-glucose (2-NBDG) assay to determine the glucose uptake activity; colourimetric total collagen assay to quantify the total collagen expression levels; COL-I ELISA assay to measure the COL-I expression levels and real-time qPCR to analyze the mRNA gene expressions levels of Scleraxis (SCX), Mohawk (MKX), type I collagen (COL1A1), type III collagen (COL3A1), matrix metalloproteinases (MMP)-9 and MMP-13 in hTeno when treated with TNF-α. Apoptosis assay for hTeno induced with TNF-α was conducted using Annexin-V FITC flow cytometry analysis.

    Results: Immunofluorescence imaging showed the presence of INSR-β on the hTeno in the human Achilles tendon tissues and in the hTeno in monolayer culture. GLUT1 and GLUT4 were both positively expressed in the hTeno. TNF-α significantly reduced the insulin-mediated 2-NBDG uptake in all the tested concentrations, especially at 0.008 µM. Total collagen expression levels and COL-I expression levels in hTeno were also significantly reduced in hTeno treated with 0.008 µM of TNF-α. The SCX, MKX and COL1A1 mRNA expression levels were significantly downregulated in all TNF-α treated hTeno, whereas the COL3A1, MMP-9 and MMP-13 were significantly upregulated in the TNF-α treated cells. TNF-α progressively increased the apoptotic cells at 48 and 72 h.

    Conclusion: At 0.008 µM of TNF-α, an IR condition was induced in hTeno, supported with the significant reduction in glucose uptake, as well as significantly reduced total collagen, specifically COL-I expression levels, downregulation of candidate tenogenic markers genes (SCX and MKX), and upregulation of ECM catabolic genes (MMP-9 and MMP-13). Development of novel IR model in hTeno provides an insight on how tendon homeostasis could be affected and can be used as a tool for further discovering the effects on downstream molecular pathways, as the implication for diabetic tendinopathy.

    Matched MeSH terms: Collagen Type I; Collagen Type III
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