Displaying publications 241 - 260 of 701 in total

Abstract:
Sort:
  1. Yin Lee JP, Thomas AJ, Lum SK, Shamsudin NH, Hii LW, Mai CW, et al.
    Surg Oncol, 2021 Jun;37:101536.
    PMID: 33677364 DOI: 10.1016/j.suronc.2021.101536
    INTRODUCTION: Fibroadenomas of the breast present as two phenotypic variants. The usual variety is 5 cm or less in diameter and there is another large variant called giant fibroadenoma which is greater than 5 cm in diameter. Despite of its large size, it is not malignant. The aim of our study is to determine whether this large variant is different from the usual fibroadenoma in terms of its biological pathways and biomarkers.

    METHODS: mRNA was extracted from 44 fibroadenomas and 36 giant fibroadenomas, and transcriptomic profiling was performed to identify up- and down-regulated genes in the giant fibroadenomas as compared to the fibroadenomas.

    RESULTS: A total of 40 genes were significantly up-regulated and 18 genes were significantly down-regulated in the giant fibroadenomas as compared to the fibroadenomas of the breast. The top 5 up-regulated genes were FN1, IL3, CDC6, FGF8 and BMP8A. The top 5 down-regulated genes were TNR, CDKN2A, COL5A1, THBS4 and BMPR1B. The differentially expressed genes (DEGs) were found to be associated with 5 major canonical pathways involved in cell growth (PI3K-AKT, cell cycle regulation, WNT, and RAS signalling) and immune response (JAK-STAT signalling). Further analyses using 3 supervised learning algorithms identified an 8-gene signature (FN1, CDC6, IL23A, CCNA1, MCM4, FLT1, FGF22 and COL5A1) that could distinguish giant fibroadenomas from fibroadenomas with high predictive accuracy.

    CONCLUSION: Our findings demonstrated that the giant fibroadenomas are biologically distinct to fibroadenomas of the breast with overexpression of genes involved in the regulation of cell growth and immune response.

    Matched MeSH terms: Signal Transduction/physiology*
  2. Haque MA, Jantan I, Harikrishnan H, Abdul Wahab SM
    Planta Med, 2018 Nov;84(17):1255-1264.
    PMID: 29906814 DOI: 10.1055/a-0637-9936
    Magnoflorine, a major bioactive metabolite isolated from Tinospora crispa, has been reported for its diverse biochemical and pharmacological properties. However, there is little report on its underlying mechanisms of action on immune responses, particularly on macrophage activation. In this study, we aimed to investigate the effects of magnoflorine, isolated from T. crispa on the pro-inflammatory mediators generation induced by LPS and the concomitant NF-κB, MAPKs, and PI3K-Akt signaling pathways in U937 macrophages. Differentiated U937 macrophages were treated with magnoflorine and the release of pro-inflammatory mediators was evaluated through ELISA, while the relative mRNA expression of the respective mediators was quantified through qRT-PCR. Correspondingly, western blotting was executed to observe the modulatory effects of magnoflorine on the expression of various markers related to NF-κB, MAPK and PI3K-Akt signaling activation in LPS-primed U937 macrophages. Magnoflorine significantly enhanced the upregulation of TNF-α, IL-1β, and PGE2 production as well as COX-2 protein expression. Successively, magnoflorine prompted the mRNA transcription level of these pro-inflammatory mediators. Magnoflorine enhanced the NF-κB activation by prompting p65, IκBα, and IKKα/β phosphorylation as well as IκBα degradation. Besides, magnoflorine treatments concentration-dependently augmented the phosphorylation of JNK, ERK, and p38 MAPKs as well as Akt. The immunoaugmenting effects were further confirmed by investigating the effects of magnoflorine on specific inhibitors, where the treatment with specific inhibitors of NF-κB, MAPKs, and PI3K-Akt proficiently blocked the magnoflorine-triggered TNF-α release and COX-2 expression. Magnoflorine furthermore enhanced the MyD88 and TLR4 upregulation. The results suggest that magnoflorine has high potential on augmenting immune responses.
    Matched MeSH terms: Signal Transduction/drug effects*
  3. Vrzalikova K, Ibrahim M, Vockerodt M, Perry T, Margielewska S, Lupino L, et al.
    Leukemia, 2018 01;32(1):214-223.
    PMID: 28878352 DOI: 10.1038/leu.2017.275
    The Hodgkin/Reed-Sternberg cells of classical Hodgkin lymphoma (HL) are characterised by the aberrant activation of multiple signalling pathways. Here we show that a subset of HL displays altered expression of sphingosine-1-phosphate (S1P) receptors (S1PR)s. S1P activates phosphatidylinositide 3-kinase (PI3-K) in these cells that is mediated by the increased expression of S1PR1 and the decreased expression of S1PR2. We also showed that genes regulated by the PI3-K signalling pathway in HL cell lines significantly overlap with the transcriptional programme of primary HRS cells. Genes upregulated by the PI3-K pathway included the basic leucine zipper transcription factor, ATF-like 3 (BATF3), which is normally associated with the development of dendritic cells. Immunohistochemistry confirmed that BATF3 was expressed in HRS cells of most HL cases. In contrast, in normal lymphoid tissues, BATF3 expression was confined to a small fraction of CD30-positive immunoblasts. Knockdown of BATF3 in HL cell lines revealed that BATF3 contributed to the transcriptional programme of primary HRS cells, including the upregulation of S1PR1. Our data suggest that disruption of this potentially oncogenic feedforward S1P signalling loop could provide novel therapeutic opportunities for patients with HL.
    Matched MeSH terms: Signal Transduction/genetics*
  4. Sayem ASM, Arya A, Karimian H, Krishnasamy N, Ashok Hasamnis A, Hossain CF
    Molecules, 2018 Jan 28;23(2).
    PMID: 29382104 DOI: 10.3390/molecules23020258
    Diabetes is associated with obesity, generally accompanied by a chronic state of oxidative stress and redox imbalances which are implicated in the progression of micro- and macro-complications like heart disease, stroke, dementia, cancer, kidney failure and blindness. All these complications rise primarily due to consistent high blood glucose levels. Insulin and glucagon help to maintain the homeostasis of glucose and lipids through signaling cascades. Pancreatic hormones stimulate translocation of the glucose transporter isoform 4 (GLUT4) from an intracellular location to the cell surface and facilitate the rapid insulin-dependent storage of glucose in muscle and fat cells. Malfunction in glucose uptake mechanisms, primarily contribute to insulin resistance in type 2 diabetes. Plant secondary metabolites, commonly known as phytochemicals, are reported to have great benefits in the management of type 2 diabetes. The role of phytochemicals and their action on insulin signaling pathways through stimulation of GLUT4 translocation is crucial to understand the pathogenesis of this disease in the management process. This review will summarize the effects of phytochemicals and their action on insulin signaling pathways accelerating GLUT4 translocation based on the current literature.
    Matched MeSH terms: Signal Transduction/drug effects*
  5. Yap WY, Hwang JS
    Molecules, 2018 Oct 04;23(10).
    PMID: 30287801 DOI: 10.3390/molecules23102537
    A group of stable, water-soluble and membrane-bound proteins constitute the pore forming toxins (PFTs) in cnidarians. They interact with membranes to physically alter the membrane structure and permeability, resulting in the formation of pores. These lesions on the plasma membrane causes an imbalance of cellular ionic gradients, resulting in swelling of the cell and eventually its rupture. Of all cnidarian PFTs, actinoporins are by far the best studied subgroup with established knowledge of their molecular structure and their mode of pore-forming action. However, the current view of necrotic action by actinoporins may not be the only mechanism that induces cell death since there is increasing evidence showing that pore-forming toxins can induce either necrosis or apoptosis in a cell-type, receptor and dose-dependent manner. In this review, we focus on the response of the cellular immune system to the cnidarian pore-forming toxins and the signaling pathways that might be involved in these cellular responses. Since PFTs represent potential candidates for targeted toxin therapy for the treatment of numerous cancers, we also address the challenge to overcoming the immunogenicity of these toxins when used as therapeutics.
    Matched MeSH terms: Signal Transduction/drug effects
  6. Huang TT, Chen CM, Lin SS, Lan YW, Cheng HC, Choo KB, et al.
    Int J Mol Sci, 2023 May 31;24(11).
    PMID: 37298555 DOI: 10.3390/ijms24119606
    E7050 is an inhibitor of VEGFR2 with anti-tumor activity; however, its therapeutic mechanism remains incompletely understood. In the present study, we aim to evaluate the anti-angiogenic activity of E7050 in vitro and in vivo and define the underlying molecular mechanism. It was observed that treatment with E7050 markedly inhibited proliferation, migration, and capillary-like tube formation in cultured human umbilical vein endothelial cells (HUVECs). E7050 exposure in the chick embryo chorioallantoic membrane (CAM) also reduced the amount of neovessel formation in chick embryos. To understand the molecular basis, E7050 was found to suppress the phosphorylation of VEGFR2 and its downstream signaling pathway components, including PLCγ1, FAK, Src, Akt, JNK, and p38 MAPK in VEGF-stimulated HUVECs. Moreover, E7050 suppressed the phosphorylation of VEGFR2, FAK, Src, Akt, JNK, and p38 MAPK in HUVECs exposed to MES-SA/Dx5 cells-derived conditioned medium (CM). The multidrug-resistant human uterine sarcoma xenograft study revealed that E7050 significantly attenuated the growth of MES-SA/Dx5 tumor xenografts, which was associated with inhibition of tumor angiogenesis. E7050 treatment also decreased the expression of CD31 and p-VEGFR2 in MES-SA/Dx5 tumor tissue sections in comparison with the vehicle control. Collectively, E7050 may serve as a potential agent for the treatment of cancer and angiogenesis-related disorders.
    Matched MeSH terms: Signal Transduction*
  7. Seow SLS, Hong SL, Lee GS, Malek SNA, Sabaratnam V
    BMC Complement Altern Med, 2017 Jun 24;17(1):334.
    PMID: 28646880 DOI: 10.1186/s12906-017-1837-6
    BACKGROUND: Ginger is a popular spice and food preservative. The rhizomes of the common ginger have been used as traditional medicine to treat various ailments. 6-Shogaol, a pungent compound isolated from the rhizomes of jahe gajah (Zingiber officinale var officinale) has shown numerous pharmacological activities, including neuroprotective and anti-neuroinflammatory activities. The aim of this study was to investigate the potential of 6-shogaol to mimic the neuritogenic activity of nerve growth factor (NGF) in rat pheochromocytoma (PC-12) cells.

    METHODS: The cytotoxic effect of 6-shogaol was determined by 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The neuritogenic activity was assessed by neurite outgrowth stimulation assay while the concentration of extracellular NGF in cell culture supernatant was assessed by enzyme-linked immunosorbent assay (ELISA). Involvement of cellular signaling pathways, mitogen-activated protein kinase kinase/extracellular signal-regulated kinase1/2 (MEK/ERK1/2) and phosphoinositide-3-kinase/protein kinase B (PI3K/AKT) in 6-shogaol-stimulated neuritogenesis were examined by using specific pharmacological inhibitors.

    RESULTS: 6-Shogaol (500 ng/ml) induced neuritogenesis that was comparable to NGF (50 ng/ml) and was not cytotoxic towards PC-12 cells. 6-Shogaol induced low level of NGF biosynthesis in PC-12 cells, showing that 6-shogaol stimulated neuritogenesis possibly by inducing NGF biosynthesis, and also acting as a substitute for NGF (NGF mimic) in PC-12 cells. The inhibitors of Trk receptor (K252a), MEK/ERK1/2 (U0126 and PD98059) and PI3K/AKT (LY294002) attenuated the neuritogenic activity of both NGF and 6-shogaol, respectively.

    CONCLUSIONS: The present findings demonstrated that 6-shogaol induced neuritogenic activity in PC-12 cells via the activation MEK/ERK1/2 and PI3K/AKT signaling pathways. This study suggests that 6-shogaol could act as an NGF mimic, which may be beneficial for preventive and therapeutic uses in neurodegenerative diseases.

    Matched MeSH terms: Signal Transduction/drug effects
  8. Razali NN, Raja Ali RA, Muhammad Nawawi KN, Yahaya A, Mohd Rathi ND, Mokhtar NM
    World J Gastroenterol, 2023 Oct 28;29(40):5543-5556.
    PMID: 37970476 DOI: 10.3748/wjg.v29.i40.5543
    BACKGROUND: Phosphatidylinositol-3-kinases (PI3K) is a well-known route in inflammation-related cancer. Recent discovery on PI3K-related genes revealed a potential variant that links ulcerative colitis (UC) and colorectal cancer (CRC) with colitis-associated cancer (CAC). PI3K/AKT pathway has been recommended as a potential additional therapeutic option for CRC due to its substantial role in modifying cellular processes. Buparlisib is a pan-class I PI3K inhibitor previously shown to reduce tumor growth.

    AIM: To investigate the regulation of rs10889677 and the role of buparlisib in the PI3K signaling pathway in CAC pathogenesis.

    METHODS: Genomic DNA from 32 colonic samples, including CAC (n = 7), UC (n = 10) and CRC (n = 15), was sequenced for the rs10889677 mutation. The mutant and wildtype fragments were amplified and cloned in the pmirGLO vector. The luciferase activity of cloned vectors was assessed after transfection into the HT29 cell line. CAC mice were induced by a mixture of a single azoxymethane injection and three cycles of dextran sulphate sodium, then buparlisib was administered after 14 d. The excised colon was subjected to immunohistochemistry for Ki67 and Cleaved-caspase-3 markers and quantitative real-time polymerase chain reaction analysis for Pdk1 and Sgk2.

    RESULTS: Luciferase activity decreased by 2.07-fold in the rs10889677 mutant, confirming the hypothesis that the variant disrupted miRNA binding sites, which led to an increase in IL23R expression and the activation of the PI3K signaling pathway. Furthermore, CAC-induced mice had a significantly higher disease activity index (P < 0.05). Buparlisib treatment significantly decreased mean weight loss in CAC-induced mice (P < 0.05), reduced the percentage of proliferating cells by 5%, and increased the number of apoptotic cells. The treatment also caused a downward trend of Pdk1 expression and significantly decreased Sgk2 expression.

    CONCLUSION: Our findings suggested that the rs10889677 variant as a critical initiator of the PI3K signaling pathway, and buparlisib had the ability to prevent PI3K-non-AKT activation in the pathophysiology of CAC.

    Matched MeSH terms: Signal Transduction/genetics
  9. Sisin NNT, Kong AR, Edinur HA, Jamil NIN, Che Mat NF
    Appl Biochem Biotechnol, 2024 Jul;196(7):4234-4255.
    PMID: 37922032 DOI: 10.1007/s12010-023-04762-w
    E6 and E7 human papillomavirus (HPV) oncoproteins play a significant role in the malignant transformation of infected cervical cancer cells via suppression of tumour suppressor pathways by targeting p53 and pRb, respectively. This study aimed to investigate the anticancer effects of Oroxylum indicum (OI) leaves' methanol extract on SiHa cervical cancer cells. Expression of apoptosis-related proteins (Bcl-2, caspase (cas)-3, and cas-9), viral oncoproteins (E6 and E7), and tumour suppressor proteins (p53 and pRb) were evaluated using western blot analysis before and after E6/E7 small interfering RNAs (siRNAs) transfection. In addition, the E6/E7 mRNA expression levels were assessed with real-time (RT)-PCR. The present study showed that the OI extract effectively hindered the proliferation of SiHa cells and instigated increments of cas-3 and cas-9 expressions but decreased the Bcl-2 expressions. The OI extract inhibited E6/E7 viral oncoproteins, leading to upregulation of p53 and pRb tumour suppressor genes in SiHa cells. Additionally, combinatorial treatment of OI extract and gossypin flavonoid induced restorations of p53 and pRb. Treatment with OI extract in siRNA-transfected cells also further suppressed E6/E7 expression levels and further upregulations of p53 and pRb proteins. In conclusion, OI extract treatment on siRNAs-transfected SiHa cells can additively and effectively block E6- and E7-dependent p53 and pRb degradations. All these data suggest that OI could be explored for its chemotherapeutic potential in cervical cancer cells with HPV-integrated genomes.
    Matched MeSH terms: Signal Transduction/drug effects
  10. Ismail NI, Othman I, Abas F, H Lajis N, Naidu R
    Int J Mol Sci, 2019 May 17;20(10).
    PMID: 31108984 DOI: 10.3390/ijms20102454
    Colorectal cancer (CRC) is among the top three cancer with higher incident and mortality rate worldwide. It is estimated that about over than 1.1 million of death and 2.2 million new cases by the year 2030. The current treatment modalities with the usage of chemo drugs such as FOLFOX and FOLFIRI, surgery and radiotherapy, which are usually accompanied with major side effects, are rarely cured along with poor survival rate and at higher recurrence outcome. This trigger the needs of exploring new natural compounds with anti-cancer properties which possess fewer side effects. Curcumin, a common spice used in ancient medicine was found to induce apoptosis by targeting various molecules and signaling pathways involved in CRC. Disruption of the homeostatic balance between cell proliferation and apoptosis could be one of the promoting factors in colorectal cancer progression. In this review, we describe the current knowledge of apoptosis regulation by curcumin in CRC with regard to molecular targets and associated signaling pathways.
    Matched MeSH terms: Signal Transduction/drug effects
  11. Tew WY, Tan CS, Yan CS, Loh HW, Wang X, Wen X, et al.
    Hypertens Res, 2024 Sep;47(9):2416-2434.
    PMID: 38914702 DOI: 10.1038/s41440-024-01652-4
    Hesperetin is one of the prominent flavonoids found in citrus fruit. Several research studies have reported that hesperetin can promote vasodilation in vascular tissue by increasing the level of nitric oxide and cyclic nucleotides. However, these may not be the only pathway for hesperetin to exert its vasodilatory effect. In addition to vasodilation, hesperetin has been found to carry an antihypertensive effect through intraperitoneal injection, although no study has comprehensively investigated the antihypertensive effect of hesperetin through oral administration. Therefore, this study aimed to determine the possible mechanism pathways involved in hesperetin-induced vasodilation and investigated its antihypertensive effects on hypertensive rats' model via oral administration. The ex vivo experimental findings showed that the NO/sGC/cGMP signalling pathway was involved in hesperetin-mediated vasodilation. Moreover, hesperetin activated the AC/cAMP/PKA pathway through PGI2 and activated the β2-adrenergic receptor. Hesperetin can act as a voltage-gated potassium channel (KV) and ATP-sensitive potassium channel (KATP) opener. The intracellular calcium in vascular smooth muscle was reduced by hesperetin through blocking the voltage-operated calcium channels (VOCC) and inositol triphosphate receptor (IP3R). In the in vivo assessment, hesperetin shows a significant decrease in Spontaneously Hypertensive rats' blood pressure following 21 days of oral treatment. The sub-chronic toxicity assessment demonstrated that hesperetin exhibited no deleterious effects on the body weights, clinical biochemistry and haematological profile of Sprague-Dawley rats. This study implies that hesperetin holds promise as a potential medication for hypertension treatment, devoid of undesirable side effects.
    Matched MeSH terms: Signal Transduction/drug effects
  12. Chai AWY, Tan YH, Ooi S, Yee PS, Yee SM, Lightfoot H, et al.
    Cancer Res Commun, 2024 Nov 01;4(11):2919-2932.
    PMID: 39360810 DOI: 10.1158/2767-9764.CRC-24-0136
    Mechanistically guided drug repurposing has been made possible by systematically integrating pharmacologic and CRISPR-Cas9 screen data. Our study discovers the biomarker and cell death mechanisms underpinning sensitivity toward AZD5582, an antagonist of the inhibitor of apoptosis family protein. Our findings have important implications for improving future trial design for patients with OSCC using this emerging drug class.
    Matched MeSH terms: Signal Transduction/drug effects
  13. Norazmi MN, Mohamed R, Nurul AA, Yaacob NS
    Clin. Dev. Immunol., 2012;2012:849195.
    PMID: 22548115 DOI: 10.1155/2012/849195
    Given their roles in immune regulation, the expression of the nuclear receptor peroxisome proliferator-activated receptor γ (PPARγ) 1 and 2 isoforms was investigated in human naïve (CD45RA+) and memory (CD45RO+) CD4+ T cells. Stimulation of both types of cells via the CD3/CD28 pathway resulted in high expression of both PPARγ receptors as measured by real-time PCR. Treatment with the PPARγ agonist, ciglitazone, increased PPARγ1 expression but decreased PPARγ2 expression in stimulated naïve and memory cells. Furthermore, when present, the magnitude of both PPARγ receptors expression was lower in naïve cells, perhaps suggesting a lower regulatory control of these cells. Similar profiles of selected proinflammatory cytokines were expressed by the two cell types following stimulation. The induction of PPARγ1 and suppression of PPARγ2 expressions in naïve and memory CD4+ T cells in the presence of ciglitazone suggest that the PPARγ subtypes may have different roles in the regulation of T-cell function.
    Matched MeSH terms: Signal Transduction/drug effects; Signal Transduction/immunology
  14. Ooi KL, Tengku Muhammad TS, Lim CH, Sulaiman SF
    Integr Cancer Ther, 2010 Mar;9(1):73-83.
    PMID: 20150224 DOI: 10.1177/1534735409356443
    The chloroform extract of Physalis minima produced a significant growth inhibition against human T-47D breast carcinoma cells as compared with other extracts with an EC(50) value of 3.8 microg/mL. An analysis of cell death mechanisms indicated that the extract elicited an apoptotic cell death. mRNA expression analysis revealed the coregulation of apoptotic genes, that is, c-myc , p53, and caspase-3. The c-myc was significantly induced by the chloroform extract at the earlier phase of treatment, followed by p53 and caspase-3. Biochemical assay and ultrastructural observation displayed typical apoptotic features in the treated cells, including DNA fragmentation, blebbing and convolution of cell membrane, clumping and margination of chromatin, and production of membrane-bound apoptotic bodies. The presence of different stages of apoptotic cell death and phosphatidylserine externalization were further reconfirmed by annexin V and propidium iodide staining. Thus, the results from this study strongly suggest that the chloroform extract of P. minima induced apoptotic cell death via p53-, caspase-3-, and c-myc-dependent pathways.
    Matched MeSH terms: Signal Transduction/drug effects; Signal Transduction/physiology
  15. Mohamed SIA, Jantan I, Nafiah MA, Seyed MA, Chan KM
    Curr Pharm Biotechnol, 2021;22(2):262-273.
    PMID: 32532192 DOI: 10.2174/1389201021666200612173029
    BACKGROUND: The anticancer effects of Phyllanthus amarus extract on various cancer cells have been investigated, however, the effects of its major constituents on HCT116 human colorectal cancer cells have not been reported.

    OBJECTIVE: In the present study, we investigated the cytotoxic effect of 80% ethanol extract of P. amarus and its marker constituents (phyllanthin, hypophyllanthin, gallic acid, niranthin, greraniin, phyltetralin, isolintetralin, corilagin and ellagic acid) on HCT116 and their underlying mechanisms of action.

    METHODS: Their antiproliferative and apoptotic effects on HCT 116 were performed using MTT assay and flow cytometric analysis, respectively, while caspases 3/7, 8 and 9 activities were examined using the colorimetric method. The expression of cleaved poly ADP ribose polymerase enzyme (PARP) and cytochrome c proteins was investigated by the immune-blot technique.

    RESULTS AND DISCUSSION: HPLC and LC-MS/MS analyses demonstrated that the extract contained mainly lignans and polyphenols. The plant samples markedly suppressed the growth and expansion of HCT116 cells in a concentration- and time-dependent manner with no toxicity against normal human fibroblast CCD18 Co. P. amarus extract, phyllanthin and gallic acid induced mode of cell death primarily through apoptosis as confirmed by the exteriorization of phosphatidylserine. Caspases 3/7, 8, and 9 activities increased in a concentration-dependent manner following 24h treatment. The expressions of cleaved PARP (Asp 214) and cytochrome c were markedly upregulated.

    CONCLUSION: P. amarus extract, phyllanthin and gallic acid exhibited an apoptotic effect on HCT116 cells through the caspases-dependent pathway.

    Matched MeSH terms: Signal Transduction/drug effects; Signal Transduction/physiology
  16. Loh SC, Thottathil GP, Othman AS
    Plant Physiol Biochem, 2016 Oct;107:45-55.
    PMID: 27236227 DOI: 10.1016/j.plaphy.2016.05.011
    The natural rubber of Para rubber tree, Hevea brasiliensis, is the main crop involved in industrial rubber production due to its superior quality. The Hevea bark is commercially exploited to obtain latex, which is produced from the articulated secondary laticifer. The laticifer is well defined in the aspect of morphology; however, only some genes associated with its development have been reported. We successfully induced secondary laticifer in the jasmonic acid (JA)-treated and linolenic acid (LA)-treated Hevea bark but secondary laticifer is not observed in the ethephon (ET)-treated and untreated Hevea bark. In this study, we analysed 27,195 gene models using NimbleGen microarrays based on the Hevea draft genome. 491 filtered differentially expressed (FDE) transcripts that are common to both JA- and LA-treated bark samples but not ET-treated bark samples were identified. In the Eukaryotic Orthologous Group (KOG) analysis, 491 FDE transcripts belong to different functional categories that reflect the diverse processes and pathways involved in laticifer differentiation. In the Kyoto Encyclopedia of Genes and Genomes (KEGG) and KOG analysis, the profile of the FDE transcripts suggest that JA- and LA-treated bark samples have a sufficient molecular basis for secondary laticifer differentiation, especially regarding secondary metabolites metabolism. FDE genes in this category are from the cytochrome (CYP) P450 family, ATP-binding cassette (ABC) transporter family, short-chain dehydrogenase/reductase (SDR) family, or cinnamyl alcohol dehydrogenase (CAD) family. The data includes many genes involved in cell division, cell wall synthesis, and cell differentiation. The most abundant transcript in FDE list was SDR65C, reflecting its importance in laticifer differentiation. Using the Basic Local Alignment Search Tool (BLAST) as part of annotation and functional prediction, several characterised as well as uncharacterized transcription factors and genes were found in the dataset. Hence, the further characterization of these genes is necessary to unveil their role in laticifer differentiation. This study provides a platform for the further characterization and identification of the key genes involved in secondary laticifer differentiation.
    Matched MeSH terms: Signal Transduction/drug effects; Signal Transduction/genetics*
  17. Aftab MF, Afridi SK, Mughal UR, Karim A, Haleem DJ, Kabir N, et al.
    J. Chem. Neuroanat., 2017 04;81:1-9.
    PMID: 28093241 DOI: 10.1016/j.jchemneu.2017.01.001
    Diabetes is associated with neurodegeneration. Glycation ensues in diabetes and glycated proteins cause insulin resistance in brain resulting in amyloid plaques and NFTs. Also glycation enhances gliosis by promoting neuroinflammation. Currently there is no therapy available to target neurodegenration in brain therefore, development of new therapy that offers neuroprotection is critical. The objective of this study was to evaluate mechanistic effect of isatin derivative URM-II-81, an anti-glycation agent for improvement of insulin action in brain and inhibition of neurodegenration. Methylglyoxal induced stress was inhibited by treatment with URM-II-81. Also, Ser473 and Ser9 phosphorylation of Akt and GSK-3β respectively were restored by URM-II-81. Effect of URM-II-81 on axonal integrity was studied by differentiating Neuro2A using retinoic acid. URM-II-81 restored axonal length in MGO treated cells. Its effects were also studied in high fat and low dose streptozotocin induced diabetic mice where it reduced RBG levels and inhibited glycative stress by reducing HbA1c. URM-II-81 treatment also showed inhibition of gliosis in hippocampus. Histological analysis showed reduced NFTs in CA3 hippocampal region and restoration of insulin signaling in hippocampii of diabetic mice. Our findings suggest that URM-II-81 can be developed as a new therapeutic agent for treatment of neurodegenration.
    Matched MeSH terms: Signal Transduction/drug effects; Signal Transduction/physiology*
  18. Al-Rawashde FA, Wan Taib WR, Ismail I, Johan MF, Al-Wajeeh AS, Al-Jamal HAN
    Asian Pac J Cancer Prev, 2021 Dec 01;22(12):3959-3965.
    PMID: 34967577 DOI: 10.31557/APJCP.2021.22.12.3959
    OBJECTIVE: BCR ABL oncogene encodes the BCR-ABL chimeric protein, which is a constitutively activated non-receptor tyrosine kinase. The BCR-ABL oncoprotein is a key molecular basis for the pathogenesis of chronic myeloid leukemia (CML) via activation of several downstream signaling pathways including JAK/STAT pathway. Development of leukemia involves constitutive activation of signaling molecules including, JAK2, STAT3, STAT5A and STAT5B. Thymoquinone (TQ) is a bioactive constituent of Nigella sativa that has shown anticancer properties in various cancers. The present study aimed to evaluate the effect of TQ on the expression of BCR ABL, JAK2, STAT3, STAT5A and STAT5B genes and their consequences on the cell proliferation and apoptosis in K562 CML cells.

    METHODS: BCR-ABL positive K562 CML cells were treated with TQ. Cytotoxicity was determined by Trypan blue exclusion assay. Apoptosis assay was performed by annexin V-FITC/PI staining assay and analyzed by flow cytometry. Transcription levels of BCR ABL, JAK2, STAT3, STAT5A and STAT5B genes were evaluated by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Protein levels of JAK2 and STAT5 were determined by Jess Assay analysis.

    RESULTS: TQ markedly decreased the cell proliferation and induced apoptosis in K562 cells (P < 0.001) in a concentration dependent manner. TQ caused a significant decrease in the transcriptional levels of BCR ABL, JAK2, STAT3, STAT5A and STAT5B genes (P < 0.001). TQ induced a significant decrease in JAK2 and STAT5 protein levels (P < 0.001).

    CONCLUSION: our results indicated that TQ inhibited cell growth of K562 cells via downregulation of BCR ABL/ JAK2/STAT3 and STAT5 signaling and reducing JAK2 and STAT5 protein levels.

    Matched MeSH terms: Signal Transduction/drug effects*; Signal Transduction/genetics
  19. van Sleen Y, Jiemy WF, Pringle S, van der Geest KSM, Abdulahad WH, Sandovici M, et al.
    Arthritis Rheumatol, 2021 12;73(12):2327-2337.
    PMID: 34105308 DOI: 10.1002/art.41887
    OBJECTIVE: Macrophages mediate inflammation, angiogenesis, and tissue destruction in giant cell arteritis (GCA). Serum levels of the macrophage-associated protein YKL-40 (chitinase 3-like protein 1), previously linked to angiogenesis and tissue remodeling, remain elevated in GCA despite glucocorticoid treatment. This study was undertaken to investigate the contribution of YKL-40 to vasculopathy in GCA.

    METHODS: Immunohistochemistry was performed on GCA temporal artery biopsy specimens (n = 12) and aortas (n = 10) for detection of YKL-40, its receptor interleukin-13 receptor α2 (IL-13Rα2), macrophage markers PU.1 and CD206, and the tissue-destructive protein matrix metalloproteinase 9 (MMP-9). Ten noninflamed temporal artery biopsy specimens served as controls. In vitro experiments with granulocyte-macrophage colony-stimulating factor (GM-CSF)- or macrophage colony-stimulating factor (M-CSF)-skewed monocyte-derived macrophages were conducted to study the dynamics of YKL-40 production. Next, small interfering RNA-mediated knockdown of YKL-40 in GM-CSF-skewed macrophages was performed to study its effect on MMP-9 production. Finally, the angiogenic potential of YKL-40 was investigated by tube formation experiments using human microvascular endothelial cells (HMVECs).

    RESULTS: YKL-40 was abundantly expressed by a CD206+MMP-9+ macrophage subset in inflamed temporal arteries and aortas. GM-CSF-skewed macrophages from GCA patients, but not healthy controls, released significantly higher levels of YKL-40 compared to M-CSF-skewed macrophages (P = 0.039). In inflamed temporal arteries, IL-13Rα2 was expressed by macrophages and endothelial cells. Functionally, knockdown of YKL-40 led to a 10-50% reduction in MMP-9 production by macrophages, whereas exposure of HMVECS to YKL-40 led to significantly increased tube formation.

    CONCLUSION: In GCA, a GM-CSF-skewed, CD206+MMP-9+ macrophage subset expresses high levels of YKL-40 which may stimulate tissue destruction and angiogenesis through IL-13Rα2 signaling. Targeting YKL-40 or GM-CSF may inhibit macrophages that are currently insufficiently suppressed by glucocorticoids.

    Matched MeSH terms: Signal Transduction/drug effects; Signal Transduction/physiology
  20. Yam MF, Tan CS, Ahmad M, Ruan S
    Am J Chin Med, 2016;44(7):1413-1439.
    PMID: 27785939
    Orthosiphon stamineus Benth. (Lamiaceae) is an important plant in traditional folk medicine that is used to treat hypertension and kidney stones. In humans, this plant has been tested as an addition regiment for antihypertensive treatment. Among the treatments for hypertension, O. stamineus had been to have diuretic and vasorelaxant effects in animal models. There is still very little information regarding the vasorelaxant effect of O. stamineus. Therefore, the present study was designed to investigate the vasorelaxant activity and mechanism of action of the fractions of O. stamineus. The vasorelaxant activity and the underlying mechanisms of the chloroform fraction of the 50% methanolic extract of O. stamineus (CF) was evaluated on thoracic aortic rings isolated from Sprague Dawley rats. CF caused relaxation of the aortic ring pre-contracted with phenylephrine in the presence and absence of endothelium, and pre-contracted with potassium chloride in endothelium-intact aortic ring. In the presence of endothelium, both indomethacin (a nonselective cyclooxygenase inhibitor) and [Formula: see text]-[1,2,4]Oxadiazolo[4,3-[Formula: see text]]quinoxalin-1-one (ODQ, selective soluble guanylate cyclase inhibitor) had a small effect on the vasorelaxation response. On the other hand, in the presence of Nω-nitro-L-arginine methyl ester (L-NAME, nitric oxide synthase inhibitor), methylene blue (cyclic guanosine monophosphate lowering agent), tetraethylammonium ([Formula: see text], nonselective calcium activator [Formula: see text] channel blocker), 4-aminopyridine (4-AP, voltage-dependent [Formula: see text] channel blocker), barium chloride ([Formula: see text], inwardly rectifying [Formula: see text] channel blocker), glibenclamide (nonspecific ATP-sensitive [Formula: see text] channel blocker), atropine (muscarinic receptor blocker) and propranolol (β-adrenergic receptor blocker), the vasorelaxant effect significantly reduced the relaxation stimulated by CF. CF was also found to be active in reducing [Formula: see text] release from the sarcoplasmic reticulum and blocking calcium channels.
    Matched MeSH terms: Signal Transduction/drug effects*; Signal Transduction/physiology
Filters
Contact Us

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

External Links