Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 70
Filter
2.
Lancet Haematol ; 11(5): e368-e382, 2024 May.
Article in English | MEDLINE | ID: mdl-38697731

ABSTRACT

Diamond-Blackfan anaemia (DBA), first described over 80 years ago, is a congenital disorder of erythropoiesis with a predilection for birth defects and cancer. Despite scientific advances, this chronic, debilitating, and life-limiting disorder continues to cause a substantial physical, psychological, and financial toll on patients and their families. The highly complex medical needs of affected patients require specialised expertise and multidisciplinary care. However, gaps remain in effectively bridging scientific discoveries to clinical practice and disseminating the latest knowledge and best practices to providers. Following the publication of the first international consensus in 2008, advances in our understanding of the genetics, natural history, and clinical management of DBA have strongly supported the need for new consensus recommendations. In 2014 in Freiburg, Germany, a panel of 53 experts including clinicians, diagnosticians, and researchers from 27 countries convened. With support from patient advocates, the panel met repeatedly over subsequent years, engaging in ongoing discussions. These meetings led to the development of new consensus recommendations in 2024, replacing the previous guidelines. To account for the diverse phenotypes including presentation without anaemia, the panel agreed to adopt the term DBA syndrome. We propose new simplified diagnostic criteria, describe the genetics of DBA syndrome and its phenocopies, and introduce major changes in therapeutic standards. These changes include lowering the prednisone maintenance dose to maximum 0·3 mg/kg per day, raising the pre-transfusion haemoglobin to 9-10 g/dL independent of age, recommending early aggressive chelation, broadening indications for haematopoietic stem-cell transplantation, and recommending systematic clinical surveillance including early colorectal cancer screening. In summary, the current practice guidelines standardise the diagnostics, treatment, and long-term surveillance of patients with DBA syndrome of all ages worldwide.


Subject(s)
Anemia, Diamond-Blackfan , Consensus , Humans , Anemia, Diamond-Blackfan/diagnosis , Anemia, Diamond-Blackfan/therapy , Anemia, Diamond-Blackfan/genetics , Disease Management , Hematopoietic Stem Cell Transplantation
3.
Biomed Rep ; 19(1): 46, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37324167

ABSTRACT

Gemcitabine is a chemotherapeutic agent for pancreatic cancer treatment. It has also been demonstrated to inhibit human pancreatic cancer cell lines, MIA PaCa-2 and PANC-1. The aim of the present study was to investigate the suppressive effect of fucoxanthin, a marine carotenoid, in combination with gemcitabine on pancreatic cancer cells. MTT assays and cell cycle analysis using flow cytometry were performed to study the mechanism of action. The results revealed that combining a low dose of fucoxanthin with gemcitabine enhanced the cell viability of human embryonic kidney cells, 293, while a high dose of fucoxanthin enhanced the inhibitory effect of gemcitabine on the cell viability of this cell line. In addition, the enhanced effect of fucoxanthin on the inhibitory effect of gemcitabine on PANC-1 cells was significant (P<0.01). Fucoxanthin combined with gemcitabine also exerted significant enhancement of the anti-proliferation effect in MIA PaCa-2 cells in a concentration dependent manner (P<0.05), compared with gemcitabine treatment alone. In conclusion, fucoxanthin improved the cytotoxicity of gemcitabine on human pancreatic cancer cells at concentrations that were not cytotoxic to non-cancer cells. Thus, fucoxanthin has the potential to be used as an adjunct in pancreatic cancer treatment.

4.
Pharmaceut Med ; 37(5): 385-394, 2023 09.
Article in English | MEDLINE | ID: mdl-37368166

ABSTRACT

BACKGROUND: In Australia, facilitated regulatory pathways (FRPs) became available with the introduction of priority review (PR) in 2017 and provisional approval (PA) in 2018, which aim to facilitate expedited review and approval for novel medicines. The pathways were developed in consultation with a wide range of stakeholders and have since been utilised by pharmaceutical companies for various therapeutic products. However, the perceptions of the firsthand users of these pathways have not been evaluated in Australia. OBJECTIVES: We have conducted a survey of Australian regulatory professionals aiming to solicit the perceived benefits, barriers to utilisation, shortcomings and proposed modifications to utilising these pathways. We have also solicited the users' perspective on key aspects of the pathways, including overall satisfaction, regulatory burden, availability and ease of use of guidelines, regulator support, impact on company strategy and recommendations for improvement. METHODS: A survey was developed and distributed to Australian regulatory professionals from the pharmaceutical industry who had submission experience of new medicine applications via either PR, PA or the standard registration pathway to the Therapeutic Goods Administration (TGA). The questionnaire consisted of 44 questions with a skip logic and the option for free text comments. RESULTS: We received responses from 16/42 companies that had utilised these new pathways. Nine respondents had experience with the PR pathway and ten with the PA pathway. The respondents were generally satisfied with the effectiveness of the PR process in expediting registration approvals, but they were ambivalent towards the PA pathway in terms of overall satisfaction and timelines. Respondents expressed a desire for further improvements in the speed of approval, earlier access for patients across various pathways and introduction of new Health Technology Assessment processes for medicines approved under PA. CONCLUSION: While the FRPs have been an important and positive development in the Australian regulatory landscape, there remain opportunities for further improvements, some of which have been highlighted by this study and may help inform future regulatory decisions.


Subject(s)
Drug Approval , Drug Development , Humans , Australia , Drug Industry , Pharmaceutical Preparations , Surveys and Questionnaires
5.
Curr Drug Targets ; 24(8): 648-661, 2023.
Article in English | MEDLINE | ID: mdl-37138489

ABSTRACT

Targeting sodium-dependent glucose transporters (SGLT1 and SGLT2) represents a new class of pharmacotherapy for type 2 diabetes mellitus, a major global health issue with an increasing social and economic burden. Following recent successes in market approvals of SGLT2 inhibitors, the ongoing effort has paved the way for the discovery of novel agents via structure-activity relationship studies, preclinical and clinical testing, including SGLT2 inhibitors, SGLT1/2 dual inhibitors, and selective SGLT1 inhibitors. A growing understanding of the physiology of SGLTs allows drug developers to explore additional cardiovascular and renal protective benefits of these agents in T2DM patients at risk. This review provides an overview of the recent investigational compounds and discusses future perspectives of drug discovery in this area.


Subject(s)
Diabetes Mellitus, Type 2 , Sodium-Glucose Transporter 2 Inhibitors , Humans , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/chemically induced , Sodium-Glucose Transporter 2 Inhibitors/pharmacology , Sodium-Glucose Transporter 2 Inhibitors/therapeutic use , Hypoglycemic Agents/adverse effects , Sodium-Glucose Transporter 2/therapeutic use , Kidney
6.
Clin Epigenetics ; 15(1): 36, 2023 03 02.
Article in English | MEDLINE | ID: mdl-36864513

ABSTRACT

BACKGROUND: Selenium, an essential trace element, has previously been investigated as a pro-apoptotic and DNA demethylation agent. It sensitizes the response to chemotherapy in patients who were refractory to cytotoxic agents. Meanwhile, ferroptosis is a novel approach to cancer treatment by triggering cell death and reversing drug resistance. The role of selenium in treating cancer cells harboring druggable oncogenic alterations and its underlying mechanism are largely unknown. RESULTS: We treated lung adenocarcinoma cell lines-EGFR-mutant H1975 (H1975 EGFR p.L858R and p.T790M) and KRAS-mutant H358 (H358 KRAS p.G12C), with sodium selenite to examine its effect on cell apoptosis, ferroptosis, and DNA methylation, as well as its interaction with existing targeted therapy, osimertinib, and adagrasib. We observed selenite to be a dual apoptotic and ferroptotic agent on lung cancer cells, associated with the activation of p38-ATF4-DDIT3 axis in the unfolded protein response. Ferroptosis induction was more remarkable in H1975 than H358. Selenite also altered cellular DNA methylation machinery through downregulating DNMT1 and upregulating TET1, though not as a major mechanism of its activity. Low-dose selenite synergized with osimertinib in EGFR-mutant H1975, and with adagrasib in KRAS-mutant H358, with stronger synergism observed in H1975. CONCLUSION: These results suggest that selenite is a potential apoptotic and ferroptotic drug candidate for the treatment of especially EGFR- and potentially KRAS-mutant lung cancer.


Subject(s)
Lung Neoplasms , Selenium , Humans , Selenious Acid , Proto-Oncogene Proteins p21(ras)/genetics , ErbB Receptors/genetics , Lung Neoplasms/drug therapy , Lung Neoplasms/genetics , DNA Methylation , Mutation , Protein Kinase Inhibitors , Epigenesis, Genetic , Mixed Function Oxygenases , Proto-Oncogene Proteins/genetics
7.
Ther Innov Regul Sci ; 57(2): 271-286, 2023 03.
Article in English | MEDLINE | ID: mdl-36271207

ABSTRACT

National Regulatory Authorities (NRAs) globally are facing the challenge of evaluating pharmaceutical products in a speedy manner, whilst simultaneously ensuring adequate efficacy, safety and quality of approved products. Additionally, common expectations include that the evaluation process is competent, flexible, commensurate with risk, efficient and rapid. In 2014, the Australian regulatory system was out of step with global regulatory developments which led to a comprehensive regulatory review and reform process. As part of the reforms, two Facilitated Regulatory Pathways (FRP) were developed for prescription medicines: Priority Review (PR) and Provisional Approval (PA). Furthermore, regulatory reliance and recognition arrangements have been expanded with the Therapeutic Goods Administration (TGA) making increased use of evaluation reports by trusted NRAs. The new pathways have been utilised by the pharmaceutical industry in Australia since 2017, with the number of medicines going through these pathways gradually increasing. Additional facilitated pathways have been developed following the review, providing alternatives to the standard pathway for registration of prescription medicines in Australia. The reform is timely, helping to position Australia well in the current global regulatory climate.


Subject(s)
Prescription Drugs , Australia , Drug Industry , Prescriptions
8.
Semin Hematol ; 59(1): 30-37, 2022 01.
Article in English | MEDLINE | ID: mdl-35491056

ABSTRACT

Fanconi anemia, telomeropathies and ribosomopathies are members of the inherited bone marrow failure syndromes, rare genetic disorders that lead to failure of hematopoiesis, developmental abnormalities, and cancer predisposition. While each disorder is caused by different genetic defects in seemingly disparate processes of DNA repair, telomere maintenance, or ribosome biogenesis, they appear to lead to a common pathway characterized by premature senescence of hematopoietic stem cells. Here we review the experimental data on senescence and inflammation underlying marrow failure and malignant transformation. We conclude with a critical assessment of current and future therapies targeting these pathways in inherited bone marrow failure syndromes patients.


Subject(s)
Anemia, Aplastic , Bone Marrow Diseases , Fanconi Anemia , Anemia, Aplastic/therapy , Bone Marrow Diseases/genetics , Bone Marrow Diseases/therapy , Cellular Senescence/genetics , Congenital Bone Marrow Failure Syndromes , Fanconi Anemia/genetics , Fanconi Anemia/therapy , Humans
9.
Exp Biol Med (Maywood) ; 247(4): 330-337, 2022 02.
Article in English | MEDLINE | ID: mdl-35068219

ABSTRACT

Cytokine storm is an umbrella term that describes an inflammatory syndrome characterized by elevated levels of circulating cytokines and hyperactivation of innate and/or adaptive immune cells. One type of cytokine storm is hemophagocytic lymphohistiocytosis (HLH), which can be either primary or secondary. Severe COVID-19-associated pneumonia and acute respiratory distress syndrome (ARDS) can also lead to cytokine storm/cytokine release syndrome (CS/CRS) and, more rarely, meet criteria for the diagnosis of secondary HLH. Here, we review the immunobiology of primary and secondary HLH and examine whether COVID-19-associated CS/CRS can be discriminated from non-COVID-19 secondary HLH. Finally, we review differences in immunobiology between these different entities, which may inform both clinical diagnosis and treatment of patients.


Subject(s)
COVID-19/complications , Cytokine Release Syndrome/etiology , Cytokine Release Syndrome/therapy , Lymphohistiocytosis, Hemophagocytic/diagnosis , Lymphohistiocytosis, Hemophagocytic/etiology , Antibodies, Monoclonal/therapeutic use , Antibodies, Neutralizing/therapeutic use , Cytokine Release Syndrome/virology , Humans , Interleukin 1 Receptor Antagonist Protein/therapeutic use , Lymphohistiocytosis, Hemophagocytic/immunology , Lymphohistiocytosis, Hemophagocytic/therapy
10.
Neurorehabil Neural Repair ; 35(10): 929-937, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34510935

ABSTRACT

Background. While wrist-worn accelerometers have been used to measure upper extremity use in the past, they primarily measure arm motion and lack the ability to capture functional hand opening and grasping activities which are essential for activities of daily living. Objectives. To characterize real-world functional hand opening and grasping activities captured over multiple days in adults with stroke and in matched controls using a novel wrist-worn device. Methods. Twenty-eight individuals (fourteen individuals with stroke and 14 healthy controls) wore the devices on both wrists for 3 days. Functional hand activity was characterized by daily hand counts, hourly hand counts, and asymmetry between hands. The Mann-Whitney U test was used to evaluate differences in functional hand activities between the two groups. Results. The stroke group had 1480 and 4691 daily hand counts in their affected and nonaffected hands, respectively. The control group had 3559 and 5021 daily hand counts in their nondominant and dominant hands, respectively. Significantly fewer daily hand counts (P = .019), fewer hourly hand counts (P = .024), and a larger asymmetry index (P = .01) of the affected hand in the stroke group were found compared to that of the nondominant hand in the control group. Conclusions. Real-world functional upper extremity activity can be measured using this novel wrist-worn device. Unlike wrist-worn accelerometers, this wrist-worn device can provide a measurement of functional grasping activity. The findings have implications for clinicians and researchers to monitor and assess real-world hand activity, as well as to apply specific doses of repetitions to improve neural recovery after stroke.


Subject(s)
Hand Strength/physiology , Stroke/physiopathology , Upper Extremity/physiopathology , Wearable Electronic Devices , Aged , Female , Humans , Male , Middle Aged , Movement/physiology , Wrist/physiopathology
11.
Exp Biol Med (Maywood) ; 246(1): 5-9, 2021 01.
Article in English | MEDLINE | ID: mdl-32972235

ABSTRACT

IMPACT STATEMENT: Severe COVID-19 associated pneumonia and acute respiratory distress syndrome has recently been described with life-threatening features of cytokine storm and loosely referred to as hemophagocytic lymphohistiocytosis (HLH) or macrophage activation syndrome (MAS). Although a recent report indicated favorable responses to the interleukin-1 receptor antagonist, anakinra in eight patients with COVID-19 secondary HLH diagnosed using the HScore calculation, others have suggested that the diagnosis of secondary HLH is uncommon and that the use of the HScore has limited value in guiding immunomodulatory therapy for COVID-19. Here, we provide additional perspective on this important controversy based upon comparisons between 14 COVID-19 cytokine storm patients and 10 secondary HLH patients seen immediately prior to the pandemic. We hypothesize that identification of HLH may relate to the severity or timing of cytokine release and suggest distinguishing between cytokine release syndrome and secondary HLH, reserving the latter term for cases fulfilling diagnostic criteria.


Subject(s)
COVID-19/complications , Cytokine Release Syndrome/etiology , Lymphohistiocytosis, Hemophagocytic/etiology , Adult , Aged , Aged, 80 and over , Female , Humans , Lymphohistiocytosis, Hemophagocytic/virology , Male , Middle Aged , Splenomegaly/etiology
12.
Biochem Biophys Res Commun ; 530(1): 348-354, 2020 09 10.
Article in English | MEDLINE | ID: mdl-32828310

ABSTRACT

The circular RNA (circRNA) circEPSTI1 has been recently identified as a new cancer-associated circRNA in multiple types of cancer. However, the involvement of circEPSTI1 in non-small cell lung cancer (NSCLC) remains unexplored. The purpose of this study was to explore the expression pattern and function of circEPSTI1 in NSCLC. We found that circEPSTI1 expression was significantly elevated in NSCLC. In vitro experiments elucidated that knockdown of circEPSTI1 caused a significant reduction in NSCLC cell proliferation and invasion. Moreover, circEPSTI1 was identified as an miRNA sponge of miRNA-1248. Knockdown of circEPSTI1 markedly increased the expression of miR-1248 in NSCLC cells. Upregulation of miR-1248 significantly restricted the proliferation and invasion of NSCLC cells. Inhibition of miR-1248 promoted the proliferation and invasion of NSCLC cells and blocked the circEPSTI1 knockdown-mediated inhibitory effect on NSCLC cell proliferation and invasion. Subsequent data revealed that the tumor-promoting gene tripartite motif-containing protein 24 (TRIM24) is a target gene of miR-1248. The upregulation of TRIM24 partially reversed circEPSTI1 knockdown- or miR-1248 overexpression-induced tumor suppressive effect in NSCLC cells. In summary, our data demonstrate that downregulation of circEPSTI1 represses the proliferation and invasion of NSCLC by inhibiting TRIM24 via miR-1248 upregulation.


Subject(s)
Carcinoma, Non-Small-Cell Lung/genetics , Carrier Proteins/genetics , Lung Neoplasms/genetics , RNA, Circular/genetics , RNA, Circular/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Cell Line, Tumor , Cell Proliferation , Down-Regulation , Gene Expression Regulation, Neoplastic , Humans , Lung Neoplasms/pathology , Neoplasm Invasiveness/genetics , Neoplasm Invasiveness/pathology , Up-Regulation
13.
J Chem Theory Comput ; 16(3): 1606-1617, 2020 Mar 10.
Article in English | MEDLINE | ID: mdl-32003992

ABSTRACT

Ab initio molecular dynamics is able to predict novel reaction mechanisms by directly observing the individual reaction events that occur in simulation trajectories. In this article, we describe an approach for detecting reaction events from simulation trajectories using a physically motivated model based on time series analysis of ab initio bond orders. We found that applying a threshold to the bond order was insufficient for accurate detection, whereas peak finding on the first time derivative resulted in significantly improved accuracy. The model is trained on a reference set of reaction events representing the ideal result given unlimited computing resources. Our study includes two model systems: a heptanylium carbocation that undergoes hydride shifts and an unsaturated iron carbonyl cluster that features CO ligand migration and bridging behavior. The results indicate a high level of promise for this analysis approach to be used in mechanistic analysis of reactive AIMD simulations more generally.

14.
Acta Pharmacol Sin ; 41(5): 678-685, 2020 May.
Article in English | MEDLINE | ID: mdl-31937933

ABSTRACT

Fecal microbiota transplantation (FMT) has become an effective strategy to treat metabolic diseases, including type 2 diabetes mellitus (T2DM). We previously reported that the intestinal microbiome had significant difference between individuals with normal glucose tolerance and T2DM in Chinese Kazak ethnic group. In this study, we investigated the effects of transplanted fecal bacteria from Kazaks with normal glucose tolerance (KNGT) in db/db mice. The mice were treated with 0.2 mL of fecal bacteria solution from KNGT daily for 10 weeks. We showed that the fecal bacteria from KNGT successfully colonized in the intestinal tract of db/db mice detected on day 14. In the FMT-treated db/db mice, the levels of fasting blood glucose, postprandial glucose, total cholesterol, triglyceride, and low-density lipoprotein-cholesterol were significantly downregulated, whereas high-density lipoprotein-cholesterol levels were upregulated. In the FMT-treated db/db mice, Desulfovibrio and Clostridium coccoides levels in gut were significantly decreased, but the fecal levels of Akkermansia muciniphila and colon histone deacetylase-3 (HDAC3) protein expression were increased. At 8 weeks, both intestinal target bacteria and HDAC3 were correlated with glycolipid levels; Akkermansia muciniphila level was positively correlated with HDAC3 protein expression (r = +0.620, P = 0.037). Our results suggest that fecal bacteria from KNGT could potentially be used to treat diabetic patients.


Subject(s)
Clostridiales/metabolism , Desulfovibrio/metabolism , Diabetes Mellitus, Type 2/metabolism , Dyslipidemias/metabolism , Fecal Microbiota Transplantation , Gastrointestinal Microbiome , Akkermansia/metabolism , Animals , Diabetes Mellitus, Type 2/therapy , Disease Models, Animal , Dyslipidemias/therapy , Humans , Male , Mice
15.
Cancers (Basel) ; 11(9)2019 Sep 08.
Article in English | MEDLINE | ID: mdl-31500349

ABSTRACT

Our recent publications showed that multidrug resistance protein 2 (MRP2, encoded by the ABCC2 gene) conferred oxaliplatin resistance in human liver cancer HepG2 cells. However, the contribution of MRP2 to oxaliplatin resistance remains unclear in colorectal and pancreatic cancer lines. We investigated the effects of silencing MRP2 by siRNA on oxaliplatin accumulation and sensitivity in human colorectal cancer Caco-2 cells and pancreatic cancer PANC-1 cells. We characterized the effects of oxaliplatin on MRP2 ATPase activities using membrane vesicles. Over-expression of MRP2 (endogenously in Caco-2 and PANC-1 cells) was associated with decreased oxaliplatin accumulation and cytotoxicity, but those deficits were reversed by inhibition of MRP2 with myricetin or siRNA knockdown. Silencing MRP2 by siRNA increased oxaliplatin-induced apoptotic rate in Caco-2 and PANC-1 cells. Oxaliplatin stimulated MRP2 ATPase activity with a concentration needed to reach 50% of the maximal stimulation (EC50) value of 8.3 ± 0.7 µM and Hill slope 2.7. In conclusion, oxaliplatin is a substrate of MRP2 with possibly two binding sites, and silencing MRP2 increased oxaliplatin accumulation and cytotoxicity in two widely available gastrointestinal tumour lines (PANC-1 and Caco-2).

16.
Sci Rep ; 9(1): 2245, 2019 02 19.
Article in English | MEDLINE | ID: mdl-30783141

ABSTRACT

Oxaliplatin is important for the clinical treatment of colorectal cancer and other gastrointestinal malignancies, but tumour resistance is limiting. Several oxaliplatin transporters were previously identified but their relative contributions to determining oxaliplatin tumour responses and gastrointestinal tumour cell sensitivity to oxaliplatin remains unclear. We studied clinical associations between tumour expression of oxaliplatin transporter candidate genes and patient response to oxaliplatin, then experimentally verified associations found with MRP2 in models of human gastrointestinal cancer. Among 18 oxaliplatin transporter candidate genes, MRP2 was the only one to be differentially expressed in the tumours of colorectal cancer patients who did or did not respond to FOLFOX chemotherapy. Over-expression of MRP2 (endogenously in HepG2 and PANC-1 cells, or induced by stable transfection of HEK293 cells) decreased oxaliplatin accumulation and cytotoxicity but those deficits were reversed by inhibition of MRP2 with myricetin or siRNA knockdown. Mice bearing subcutaneous HepG2 tumour xenografts were sensitised to oxaliplatin antitumour activity by concurrent myricetin treatment with little or no increase in toxicity. In conclusion, MRP2 limits oxaliplatin accumulation and response in human gastrointestinal cancer. Screening tumour MRP2 expression levels, to select patients for treatment with oxaliplatin-based chemotherapy alone or in combination with a MRP2 inhibitor, could improve treatment outcomes.


Subject(s)
Gastrointestinal Neoplasms , Multidrug Resistance-Associated Proteins/metabolism , Neoplasm Proteins/metabolism , Oxaliplatin , Animals , Gastrointestinal Neoplasms/drug therapy , Gastrointestinal Neoplasms/metabolism , Gastrointestinal Neoplasms/pathology , HEK293 Cells , Hep G2 Cells , Humans , Mice , Mice, Nude , Multidrug Resistance-Associated Protein 2 , Oxaliplatin/pharmacokinetics , Oxaliplatin/pharmacology
17.
J Biomol Struct Dyn ; 37(15): 4070-4079, 2019 09.
Article in English | MEDLINE | ID: mdl-30449253

ABSTRACT

The interaction of trypsin with Gensenoside-Rg1 (G-Rg1) was studied using fluorescence, ultraviolet-visible (UV-vis), and circular dichroism (CD) spectroscopies along with enzyme activity assay and molecular docking. The enzyme activity assays showed that G-Rg1 inhibited the activity of trypsin effectively. The fluorescence experiments indicated that a complex of G-Rg1-trypsin was formed and that the fluorescence of trypsin was quenched by G-Rg1 via a mixed-quenching mechanism (both static and dynamic quenching). The thermodynamic analysis suggested that hydrophobic interaction and hydrogen bond were the major forces between G-Rg1 and trypsin. According to the theory of Förster's non-radiation energy transfer, the binding distance between trypsin and G-Rg1 was calculated to be 2.01 nm, which implies that energy transfer occurred within the complex. The experimental results obtained from UV-vis absorption spectra, synchronous fluorescence spectra, and CD spectra indicated that G-Rg1 was mainly located on tryptophan moiety and that the interaction between G-Rg1 and trypsin led to conformational changes of trypsin with some α-helix and unordered coil structures being transformed into ß-sheet structures. In addition, docking results supported the above experimental findings and suggested the possible binding location of G-Rg1 on trypsin along with the possible hydrogen bonds and hydrophobic interactions between G-Rg1 and trypsin. The experimental results from this study should be useful to minimize the antinutritional effects and make full use of Genseng extracts in the food industry and also be helpful to the design of the drugs for the diseases related to overexpression of trypsin. Communicated by Ramaswamy H. Sarma.


Subject(s)
Biological Products/chemistry , Molecular Docking Simulation , Molecular Dynamics Simulation , Trypsin Inhibitors/chemistry , Trypsin/chemistry , Algorithms , Binding Sites , Biological Products/pharmacology , Dose-Response Relationship, Drug , Enzyme Activation , Ligands , Models, Theoretical , Molecular Conformation , Molecular Structure , Protein Binding , Spectrum Analysis , Thermodynamics , Trypsin Inhibitors/pharmacology
18.
Mol Biol Rep ; 45(6): 1637-1646, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30215193

ABSTRACT

Study on the binding properties of helicid by pepsin systematically using multi-spectroscopic techniques and molecular docking method, and these interactions comprise biological recognition at molecular level and backbone of biological significance in medicine concerned with the uses, effects, and modes of action of drugs. We investigated the mechanism of interaction between helicid and pepsin by using various spectroscopic techniques viz., fluorescence spectra, UV-Vis absorption spectra, circular dichroism (CD), 3D spectra, synchronous fluorescence spectra and molecular docking methods. The quenching mechanism associated with the helicid-pepsin interaction was determined by performing fluorescence measurements at different temperatures. From the experimental results show that helicid quenched the fluorescence intensity of pepsin via a combination of static and dynamic quenching process. The binding constants (Ka) at three temperatures (288, 298, and 308 K) were 7.940 × 107, 2.082 × 105 and 3.199 × 105 L mol-1, respectively, and the number of binding sites (n) were 1.44, 1.14, and 1.18, respectively. The n value is close to unity, which means that there is only one independent class of binding site on pepsin for helicid. Thermodynamic parameters at 298 K were calculated as follows: ΔHo (- 83.85 kJ mol-1), ΔGo (- 33.279 kJ mol-1), and ΔSo (- 169.72 J K-1 mol-1). Based on thermodynamic analysis, the interaction of helicid with pepsin is driven by enthalpy, and Van der Waals' forces and hydrogen bonds are the main forces between helicid and pepsin. A molecular docking study further confirmed the binding mode obtained by the experimental studies. The conformational changes in the structure of pepsin was confirmed by 3D fluorescence spectra and circular dichroism.


Subject(s)
Benzaldehydes/chemistry , Pepsin A/chemistry , Binding Sites , Circular Dichroism , Fluorescence , Hydrogen Bonding , Medicine, Chinese Traditional , Molecular Docking Simulation/methods , Protein Binding/physiology , Protein Domains/physiology , Spectrometry, Fluorescence/methods , Spectrophotometry, Ultraviolet/methods , Temperature , Thermodynamics
19.
BMJ Case Rep ; 20182018 Feb 05.
Article in English | MEDLINE | ID: mdl-29437728

ABSTRACT

A 67-year-old right-handed woman presented with dysarthria, left upper extremity weakness and right-sided neglect of 3 hours duration. Imaging of the brain revealed acute right middle cerebral artery stroke; however, tissue plasminogen activator could not be administered due to severe thrombocytopenia. A peripheral smear revealed schistocytes and the patient was treated empirically for thrombotic thrombocytopenic purpura (TTP) with therapeutic plasma exchange. An extensive workup revealed no embolic source or other cause for stroke, and a diagnosis of large vessel infarct secondary to TTP was made. After a prolonged hospital course, the patient had partial neurological recovery and was discharged to a rehabilitation facility. Although transient neurologic deficits due to small vessel occlusions are well described in TTP, large vessel infarct can occur as well. This diagnosis should be considered in patients presenting with concomitant stroke and thrombocytopenia, as untreated TTP is nearly always fatal.


Subject(s)
Dysarthria/diagnosis , Purpura, Thrombotic Thrombocytopenic/diagnosis , Stroke/diagnosis , Adrenal Cortex Hormones/therapeutic use , Aged , Dysarthria/etiology , Dysarthria/physiopathology , Female , Humans , Plasma Exchange/methods , Purpura, Thrombotic Thrombocytopenic/physiopathology , Purpura, Thrombotic Thrombocytopenic/therapy , Stroke/physiopathology , Stroke/therapy , Treatment Outcome
20.
J Inorg Biochem ; 177: 249-258, 2017 12.
Article in English | MEDLINE | ID: mdl-28551160

ABSTRACT

Oxaliplatin-based chemotherapy is the mainstay for the treatment of advanced colorectal cancer. Copper transporter proteins have been implicated in the transport of platinum-based anticancer drugs, but their expression in human colorectal cancer cell lines and roles in controlling their sensitivity to oxaliplatin are not well studied or understood. The endogenous and modified expression of copper uptake transporter 1 (hCTR1) was studied in a panel of human colorectal cancer cell lines (DLD-1, SW620, HCT-15 and COLO205) with ~20-fold variation in oxaliplatin sensitivity. hCTR1 protein was expressed more abundantly than ATP7A and ATP7B proteins, but with broadly similar levels and patterns of expression across four colorectal cancer cell lines. In a colorectal cancer cell-line background (DLD-1), stable transfection of the hCtr1 gene enhanced hCTR1 protein expression and increased the sensitivity of the cells to the cytotoxicity of copper and oxaliplatin. Treatment with copper chelators (ammonium tetrathiomolybdate, bathocuproinedisulfonic acid and D-penicillamine) increased expression of hCTR1 protein in DLD-1 and SW620 cells, and potentiated the cytotoxicity of oxaliplatin in DLD-1 but not SW620 cells. Treatment with copper chloride altered neither the expression of copper transporters nor cytotoxicity of oxaliplatin in colorectal cancer lines. In conclusion, human colorectal cancer cell lines consistently express hCTR1 protein despite their variable sensitivity to oxaliplatin. Genetic or pharmacological modification of hCTR1 protein expression may potentiate oxaliplatin sensitivity in some but not all colorectal cancer cell lines.


Subject(s)
Antineoplastic Agents/pharmacology , Cation Transport Proteins/genetics , Organoplatinum Compounds/pharmacology , Cation Transport Proteins/metabolism , Cell Line, Tumor , Chelating Agents/pharmacology , Copper/metabolism , Copper Transporter 1 , Copper-Transporting ATPases/metabolism , Drug Synergism , Humans , Molybdenum/pharmacology , Organoplatinum Compounds/metabolism , Oxaliplatin , Penicillamine/pharmacology , Phenanthrolines/pharmacology , Up-Regulation/drug effects
SELECTION OF CITATIONS
SEARCH DETAIL
...