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Pediatric cancers are the leading cause of disease-related deaths in children and adolescents. Most of these tumors are difficult to treat and have poor overall survival. Concerns have also been raised about drug toxicity and long-term detrimental side effects of therapies. In this review, we discuss the advantages and unique attributes of zebrafish as pediatric cancer models and their importance in targeted drug discovery and toxicity assays. We have also placed a special focus on zebrafish models of pediatric brain cancers-the most common and difficult solid tumor to treat.
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TP53 and RB1 loss-of-function mutations are common in osteosarcoma. During development, combined loss of TP53 and RB1 function leads to downregulation of autophagy and the aberrant formation of primary cilia, cellular organelles essential for the transmission of canonical Hedgehog (Hh) signaling. Excess cilia formation then leads to hypersensitivity to Hedgehog (Hh) ligand signaling. In mouse and human models, we now show that osteosarcomas with mutations in TP53 and RB1 exhibit enhanced ligand-dependent Hh pathway activation through Smoothened (SMO), a transmembrane signaling molecule required for activation of the canonical Hh pathway. This dependence is mediated by hypersensitivity to Hh ligand and is accompanied by impaired autophagy and increased primary cilia formation and expression of Hh ligand in vivo. Using a conditional genetic mouse model of Trp53 and Rb1 inactivation in osteoblast progenitors, we further show that deletion of Smo converts the highly malignant osteosarcoma phenotype to benign, well differentiated bone tumors. Conversely, conditional overexpression of SHH ligand, or a gain-of-function SMO mutant in committed osteoblast progenitors during development blocks terminal bone differentiation. Finally, we demonstrate that the SMO antagonist sonidegib (LDE225) induces growth arrest and terminal differentiation in vivo in osteosarcomas that express primary cilia and Hh ligand combined with mutations in TP53. These results provide a mechanistic framework for aberrant Hh signaling in osteosarcoma based on defining mutations in the tumor suppressor, TP53.
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Antineoplásicos , Osteossarcoma , Humanos , Animais , Camundongos , Proteínas Hedgehog/metabolismo , Ligantes , Transdução de Sinais , Antineoplásicos/farmacologia , Osteossarcoma/genética , Osteossarcoma/metabolismo , Receptor Smoothened/genética , Receptor Smoothened/metabolismo , Cílios/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismoRESUMO
Diffuse midline gliomas (DMG), including diffuse intrinsic pontine gliomas (DIPGs), are the most lethal of childhood cancers. Palliative radiotherapy is the only established treatment, with median patient survival of 9-11 months. ONC201 is a DRD2 antagonist and ClpP agonist that has shown preclinical and emerging clinical efficacy in DMG. However, further work is needed to identify the mechanisms of response of DIPGs to ONC201 treatment and to determine whether recurring genomic features influence response. Using a systems-biological approach, we showed that ONC201 elicits potent agonism of the mitochondrial protease ClpP to drive proteolysis of electron transport chain and tricarboxylic acid cycle proteins. DIPGs harboring PIK3CA-mutations showed increased sensitivity to ONC201, while those harboring TP53-mutations were more resistant. Metabolic adaptation and reduced sensitivity to ONC201 was promoted by redox-activated PI3K/Akt signaling, which could be counteracted using the brain penetrant PI3K/Akt inhibitor, paxalisib. Together, these discoveries coupled with the powerful anti-DIPG/DMG pharmacokinetic and pharmacodynamic properties of ONC201 and paxalisib have provided the rationale for the ongoing DIPG/DMG phase II combination clinical trial NCT05009992.
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Diffuse midline gliomas (DMG), including diffuse intrinsic pontine gliomas (DIPG), are the most lethal of childhood cancers. Palliative radiotherapy is the only established treatment, with median patient survival of 9 to 11 months. ONC201 is a DRD2 antagonist and ClpP agonist that has shown preclinical and emerging clinical efficacy in DMG. However, further work is needed to identify the mechanisms of response of DIPGs to ONC201 treatment and to determine whether recurring genomic features influence response. Using a systems-biological approach, we showed that ONC201 elicits potent agonism of the mitochondrial protease ClpP to drive proteolysis of electron transport chain and tricarboxylic acid cycle proteins. DIPGs harboring PIK3CA mutations showed increased sensitivity to ONC201, whereas those harboring TP53 mutations were more resistant. Metabolic adaptation and reduced sensitivity to ONC201 was promoted by redox-activated PI3K/Akt signaling, which could be counteracted using the brain penetrant PI3K/Akt inhibitor, paxalisib. Together, these discoveries coupled with the powerful anti-DIPG/DMG pharmacokinetic and pharmacodynamic properties of ONC201 and paxalisib have provided the rationale for the ongoing DIPG/DMG phase II combination clinical trial NCT05009992. SIGNIFICANCE: PI3K/Akt signaling promotes metabolic adaptation to ONC201-mediated disruption of mitochondrial energy homeostasis in diffuse intrinsic pontine glioma, highlighting the utility of a combination treatment strategy using ONC201 and the PI3K/Akt inhibitor paxalisib.
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Pediatric solid and central nervous system tumors are the leading cause of cancer-related death among children. Identifying new targeted therapies necessitates the use of pediatric cancer models that faithfully recapitulate the patient's disease. However, the generation and characterization of pediatric cancer models has significantly lagged behind adult cancers, underscoring the urgent need to develop pediatric-focused cell line resources. Herein, we establish a single-site collection of 261 cell lines, including 224 pediatric cell lines representing 18 distinct extracranial and brain childhood tumor types. We subjected 182 cell lines to multi-omics analyses (DNA sequencing, RNA sequencing, DNA methylation), and in parallel performed pharmacological and genetic CRISPR-Cas9 loss-of-function screens to identify pediatric-specific treatment opportunities and biomarkers. Our work provides insight into specific pathway vulnerabilities in molecularly defined pediatric tumor classes and uncovers biomarker-linked therapeutic opportunities of clinical relevance. Cell line data and resources are provided in an open access portal.
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Neoplasias Encefálicas , Criança , Humanos , Neoplasias Encefálicas/patologia , Linhagem Celular TumoralRESUMO
The recent coronavirus disease 2019 (COVID-19) outbreak has drawn global attention, affecting millions, disrupting economies and healthcare modalities. With its high infection rate, COVID-19 has caused a colossal health crisis worldwide. While information on the comprehensive nature of this infectious agent, SARS-CoV-2, still remains obscure, ongoing genomic studies have been successful in identifying its genomic sequence and the presenting antigen. These may serve as promising, potential therapeutic targets in the effective management of COVID-19. In an attempt to establish herd immunity, massive efforts have been directed and driven toward developing vaccines against the SARS-CoV-2 pathogen. This review, in this direction, is aimed at providing the current scenario and future perspectives in the development of vaccines against SARS-CoV-2.
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Vacinas contra COVID-19/imunologia , COVID-19/imunologia , COVID-19/prevenção & controle , COVID-19/epidemiologia , COVID-19/virologia , Humanos , Imunidade , Imunidade Coletiva , SARS-CoV-2/isolamento & purificação , VacinaçãoRESUMO
Colorectal cancer (CRC) exhibits complex pathogenesis via compromised intestinal mucosal barrier. It is accepted that goblet cells secrete mucin which line the intestinal mucosal barrier and offer wide range protection and maintain the gut integrity. The principal mucin in the small and large intestine which is Mucin2 (MUC2) is predominantly expressed in the goblet cells which play a pivotal role in intestinal homeostasis. Its disruption is associated with diverse diseases and carcinomas. MUC2 has lately been identified as a principal marker in various mechanisms and secretory cell lineage. While MUC2 expression is regulated by various modulators, alterations in its expression are associated with immunomodulation, differences in tumor immunity and also regulation of microbiota. In the light of current literature, the present review explicates the regulation, functional mechanisms and essential role of MUC2 in colorectal cancer and aids in providing deep understanding of pathogenesis of the disease and also specifies the importance of the MUC2 in gaining more insights about the subtypes of colorectal cancer and how it can succour in approximating the prognosis and survival of the patients.
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Adenocarcinoma/metabolismo , Biomarcadores Tumorais/metabolismo , Neoplasias Colorretais/metabolismo , Mucina-2/metabolismo , Adenocarcinoma/genética , Adenocarcinoma/patologia , Animais , Biomarcadores Tumorais/genética , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Regulação Neoplásica da Expressão Gênica , Humanos , Mucina-2/genética , Prognóstico , Transdução de SinaisRESUMO
Inflammation is the result of a complex network of cellular and molecular interactions and mechanisms that facilitate immune protection against intrinsic and extrinsic stimuli, particularly pathogens, to maintain homeostasis and promote tissue healing. However, dysregulation in the immune system elicits excess/abnormal inflammation resulting in unintended tissue damage and causes major inflammatory diseases including asthma, chronic obstructive pulmonary disease, atherosclerosis, inflammatory bowel diseases, sarcoidosis and rheumatoid arthritis. It is now widely accepted that both endoplasmic reticulum (ER) stress and inflammasomes play critical roles in activating inflammatory signalling cascades. Notably, evidence is mounting for the involvement of ER stress in exacerbating inflammasome-induced inflammatory cascades, which may provide a new axis for therapeutic targeting in a range of inflammatory disorders. Here, we comprehensively review the roles, mechanisms and interactions of both ER stress and inflammasomes, as well as their interconnected relationships in inflammatory signalling cascades. We also discuss novel therapeutic strategies that are being developed to treat ER stress- and inflammasome-related inflammatory disorders.
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Asthma is a common, heterogeneous and serious disease, its prevalence has steadily risen in most parts of the world, and the condition is often inadequately controlled in many patients. Hence, there is a major need for new therapeutic approaches. Mild-to-moderate asthma is considered a T-helper cell type-2-mediated inflammatory disorder that develops due to abnormal immune responses to otherwise innocuous allergens. Prolonged exposure to allergens and persistent inflammation results in myofibroblast infiltration and airway remodelling with mucus hypersecretion, airway smooth muscle hypertrophy, and excess collagen deposition. The airways become hyper-responsive to provocation resulting in the characteristic wheezing and obstructed airflow experienced by patients. Extensive research has progressed the understanding of the underlying mechanisms and the development of new treatments for the management of asthma. Here, we review the basis of the disease, covering new areas such as the role of vascularisation and microRNAs, as well as associated potential therapeutic interventions utilising reports from animal and human studies. We also cover novel drug delivery strategies that are being developed to enhance therapeutic efficacy and patient compliance. Potential avenues to explore to improve the future of asthma management are highlighted.
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Alérgenos/imunologia , Antiasmáticos/administração & dosagem , Asma/tratamento farmacológico , Remodelação das Vias Aéreas , Animais , Asma/genética , Asma/imunologia , Sistemas de Liberação de Medicamentos , Humanos , Adesão à Medicação , MicroRNAs/genéticaRESUMO
The ongoing COVID-19 pandemic has placed a spotlight on infectious diseases and their associations with host factors and underlying conditions. New data on the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) virus are entering the public domain at a rapid rate such that their distillation often lags behind. To minimise weak associations becoming perceived as established paradigms, it is imperative that methodologies and outputs from different studies are appropriately critiqued and compared. In this review, we examine recent data on a potential relationship between smoking and COVID-19. While the causal role of smoking has been firmly demonstrated in regard to lung cancer and chronic obstructive pulmonary disease, such associations have the benefit of decades' worth of multi-centre epidemiological and mechanistic data. From our analysis of the available studies to date, it appears that a relationship is emerging in regard to patients with a smoking history having a higher likelihood of developing more severe symptoms of COVID-19 disease than non-smokers. Data on whether COVID-19 has a greater incidence in smokers than non-smokers is thus far, contradictory and inconclusive. There is therefore a need for some caution to be exercised until further research has been conducted in a wider range of geographical settings with sufficient numbers of patients that have been carefully phenotyped in respect of smoking status and adequate statistical control for confounding factors.
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COVID-19/complicações , COVID-19/epidemiologia , Fumar/efeitos adversos , Humanos , Fatores de RiscoRESUMO
Probiotics have been widely used in maintaining gastrointestinal health, despite their actual mechanism remaining obscure. There are several hypotheses behind the beneficial effects of probiotics including the regulation of intestinal barrier function and improvement in immune responses in the gastrointestinal system. Multiple probiotics have been introduced in the market as effective dietary supplements in improving gastrointestinal integrity, but there are no or few studies that demonstrate their underlying mechanism. In the current study, we investigated and compared the efficacy of four probiotics (based on different bacterial species) in refining gastrointestinal health by improving mucus biosynthesis and intestinal immune response under in-vitro conditions. By analyzing the gene expression of mucus biosynthesis and intestinal immune response markers, we found that probiotic Streptococcus thermophilus UASt-09 showed promising potential in refining mucosal barrier and gastrointestinal health in human colonic epithelial cells, as compared to other commercial probiotics.
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Despite the rarity of renal tumors in children, many different types of malignant and nonmalignant renal neoplasms have been described. Therefore, the correct diagnosis and clinical management of these patients can represent a challenge. Here we provide a comprehensive review of the commonly diagnosed pediatric renal malignancies, including nephroblastoma (commonly known as Wilms tumor), clear cell sarcoma of the kidney, rhabdoid tumor of the kidney, several subtypes of renal cell tumors (often collectively termed renal cell carcinoma), and congenital mesoblastic nephroma. The epidemiology, pathology, treatments, underlying genetic and molecular mechanisms, and proposed developmental origins are discussed in detail, highlighting differential features and potential improved therapeutic strategies for affected individuals.
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Carcinoma de Células Renais/patologia , Neoplasias Renais/patologia , Rim/patologia , Sarcoma de Células Claras/patologia , Tumor de Wilms/patologia , Criança , HumanosRESUMO
Asthma is a common, heterogeneous and serious disease with high prevalence globally. Poorly controlled, steroid-resistant asthma is particularly important as there are no effective therapies and it exerts substantial healthcare and societal burden. The role of microbiomes, particularly in chronic diseases has generated considerable interest in recent times. Existing evidence clearly demonstrates an association between asthma initiation and the microbiome, both respiratory and gastro-intestinal, although its' roles are poorly understood when assessing the asthma progression or heterogeneity (i.e. phenotypes/endotypes) across different geographical locations. Moreover, modulating microbiomes could be preventive and/or therapeutic in patients with asthma warrants urgent attention. Here, we review recent advances in assessing the role of microbiomes in asthma and present the challenges associated with the potential therapeutic utility of modifying microbiomes in management.
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Asma/microbiologia , Asma/terapia , Microbiota , Animais , Humanos , Intestinos/microbiologia , Pulmão/microbiologiaRESUMO
Mildly elevated serum unconjugated bilirubin (UCB) concentrations are associated with protection against disease conditions underpinned by cellular and metabolic stress. To determine the potential therapeutic efficacy of UCB we tested it in an in vitro model of gut inflammation. Tunicamycin TUN (10 µg/mL) was used to induce endoplasmic reticular stress (ERS) affecting N-glycosylation in LS174T cells. Cultured cells were investigated with addition of UCB at doses 0.1, 1 and 10µM (resulting in bilirubin:albumin ratios of 0.325-0.003)against ER stress-mediated effects including inflammation, cell survival (determined by apoptosis) and proliferation. Gene expression of ER stress markers (Grp78, Perk, XBP1 and ATF6) were evaluated in addition to cytokine concentrations in media after six hours of treatment. We then verified the potential role of UCB in executing programmed cell death via PARP, Caspase3 and Annexin V assays and further explored cell proliferation using the Click-iT EdU assay. A dose of 10µM UCB most potently reduced tunicamycin-mediated effects on enhanced UPR markers, inflammatory cytokines and proliferation; however all the doses (i.e.0.1-10µM) reduced the expression of ER stress and inflammatory markers Grp78, NLRP3, IL1-b, XBP1, PERK and ATF6. Furthermore, media concentrations of pro-inflammatory cytokines IL-8, IL-4 and TNFα decreased and the anti-inflammatory cytokine IL-10 increased (P<0.05). A dose of 10µM UCB initiated intrinsic apoptosis via Caspase 3 and in addition reduced cellular proliferation. Collectively, these data indicate that co treatment with UCB resulted in reducing ER stress response to TUN in gastrointestinal epithelial cells, reduced the subsequent inflammatory response, induced cancer cell death and decreased cellular proliferation. These data suggest that mildly elevated circulating or enteric UCB might protect against gastrointestinal inflammatory disorders.
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Bilirrubina/farmacologia , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/patologia , Apoptose/efeitos dos fármacos , Bilirrubina/uso terapêutico , Biomarcadores/metabolismo , Caspase 3/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/patologia , Chaperona BiP do Retículo Endoplasmático , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Células Epiteliais/patologia , Humanos , Inflamação/tratamento farmacológico , Tunicamicina/farmacologiaRESUMO
Tuberculosis (TB), caused by the bacterium Mycobacterium tuberculosis, is the leading cause of mortality worldwide due to a single infectious agent. The pathogen spreads primarily via aerosols and especially infects the alveolar macrophages in the lungs. The lung has evolved various biological mechanisms, including oxidative stress (OS) responses, to counteract TB infection. M. tuberculosis infection triggers the generation of reactive oxygen species by host phagocytic cells (primarily macrophages). The development of resistance to commonly prescribed antibiotics poses a challenge to treat TB; this commonly manifests as multidrug resistant tuberculosis (MDR-TB). OS and antioxidant defense mechanisms play key roles during TB infection and treatment. For instance, several established first-/second-line antitubercle antibiotics are administered in an inactive form and subsequently transformed into their active form by components of the OS responses of both host (nitric oxide, S-oxidation) and pathogen (catalase/peroxidase enzyme, EthA). Additionally, M. tuberculosis has developed mechanisms to survive high OS burden in the host, including the increased bacterial NADH/NAD+ ratio and enhanced intracellular survival (Eis) protein, peroxiredoxin, superoxide dismutases, and catalases. Here, we review the interplay between lung OS and its effects on both activation of antitubercle antibiotics and the strategies employed by M. tuberculosis that are essential for survival of both drug-susceptible and drug-resistant bacterial subtypes. We then outline potential new therapies that are based on combining standard antitubercular antibiotics with adjuvant agents that could limit the ability of M. tuberculosis to counter the host's OS response.
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Estresse Oxidativo , Tuberculose/patologia , Tuberculose/terapia , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Farmacorresistência Bacteriana/efeitos dos fármacos , Humanos , Pulmão/patologia , Mycobacterium tuberculosis/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Tuberculose/microbiologiaRESUMO
Sustained endoplasmic reticular stress (ERS) is implicated in aggressive metastasis of cancer cells and increased tumor cell proliferation. Cancer cells activate the unfolded protein response (UPR), which aids in cellular survival and adaptation to harsh conditions. Inhibition of apoptosis, in contrast, is a mechanism adopted by cancer cells with the help of the inhibitor of an apoptosis (IAP) class of proteins such as Survivin to evade cell death and gain a proliferative advantage. In this study, we aimed to reveal the interrelation between ERS and Survivin. We initially verified the expression of Survivin in Winnie (a mouse model of chronic ERS) colon tissues by using immunohistochemistry (IHC) and immunofluorescence (IF) in comparison with wild type Blk6 mice. Additionally, we isolated the goblet cells and determined the expression of Survivin by IF and protein validation. Tunicamycin was utilized at a concentration of 10 µg/mL to induce ERS in the LS174T cell line and the gene expression of the ERS markers was measured. This was followed by determination of inflammatory cytokines. Inhibition of ERS was carried out by 4Phenyl Butyric acid (4PBA) at a concentration of 10 mM to assess whether there was a reciprocation effect. The downstream cell death assays including caspase 3/7, Annexin V, and poly(ADP-ribose) polymerase (PARP) cleavage were evaluated in the presence of ERS and absence of ERS, which was followed by a proliferative assay (EdU click) with and without ERS. Correspondingly, we inhibited Survivin by YM155 at a concentration of 100 nM and observed the succeeding ERS markers and inflammatory markers. We also verified the caspase 3/7 assay. Our results demonstrate that ERS inhibition not only significantly reduced the UPR genes (Grp78, ATF6, PERKandXBP1) along with Survivin but also downregulated the inflammatory markers such as IL8, IL4, and IL6, which suggests a positive correlation between ERS and the inhibition of apoptosis. Furthermore, we provided evidence that ERS inhibition promoted apoptosis in LS174T cells and shortened the proliferation rate. Moreover, Survivin inhibition by YM155 led to a comparable effect as that of ERS inhibition, which includes attenuation of ERS genes and inflammatory markers as well as the promotion of programmed cell death via the caspase 3/7 pathway. Together, our results propose the interrelation between ERS and inhibition of apoptosis assigning a molecular and therapeutic target for cancer treatment.
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Initiating anti-apoptotic signaling or triggering cell death depends to a great extent on the nature or source of cellular stress and cell type. Interplay between each stress response eventually determines the fate of stressed cell. Numerous factors induce cell death by a number of pathways including apoptosis, autophagy and necrosis. Not surprisingly, some of the pathways are interrelated to each other through a mediator that could articulate the entire mechanism. The present review attempts to consolidate all the pathways included in intrinsic cellular stress such as oxidative stress and autophagy, endoplasmic reticular stress (ERS) and mitophagy and apoptosis as fate in cell stress. These stress responses are a hallmark of numerous diseases including neurodegenerative diseases, diabetes and cancer. Understanding the cross-talk between different intrinsic cell stress responses will help to develop new therapeutic targets and hence lead to the development of new therapeutics.
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Morte Celular , Estresse Oxidativo , Transdução de Sinais , Animais , HumanosRESUMO
The endoplasmic reticulum (ER) is a complex protein folding and trafficking organelle. Alteration and discrepancy in the endoplasmic reticulum environment can affect the protein folding process and hence, can result in the production of misfolded proteins. The accumulation of misfolded proteins causes cellular damage and elicits endoplasmic reticulum stress. Under such stress conditions, cells exhibit reduced functional synthesis, and will undergo apoptosis if the stress is prolonged. To resolve the ER stress, cells trigger an intrinsic mechanism called an unfolded protein response (UPR). UPR is an adaptive signaling process that triggers multiple pathways through the endoplasmic reticulum transmembrane transducers, to reduce and remove misfolded proteins and improve the protein folding mechanism, in order to improve and maintain endoplasmic reticulum homeostasis. An increasing number of studies support the view that oxidative stress has a strong connection with ER stress. During the protein folding process, reactive oxygen species are produced as by-products, leading to impaired reduction-oxidation (redox) balance conferring oxidative stress. As the protein folding process is dependent on redox homeostasis, the oxidative stress can disrupt the protein folding mechanism and enhance the production of misfolded proteins, causing further ER stress. It is proposed that endoplasmic reticulum stress and oxidative stress together play significant roles in the pathophysiology of bowel diseases.
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Estresse do Retículo Endoplasmático , Doenças Inflamatórias Intestinais/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Retículo Endoplasmático/metabolismo , Homeostase , Humanos , Estresse Oxidativo , Dobramento de Proteína , Transdução de Sinais , Resposta a Proteínas não DobradasRESUMO
BACKGROUND: Bitter Melon (BM) has been used as a functional food in traditional Chinese and Indian medicine for many generations and has gained a great deal of attention due to its apparent benefits in moderating some of the pathogenic processes in a variety of inflammatory conditions. BM extract (BME) has been shown to possess strong anti-oxidant properties. In addition, it can ameliorate oxidative stress and potentially ER stress. There is increasing evidence that oxidative and ER stress are major contributors for intestinal secretory cell dysfunction which leads to local inflammation and disease pathogenesis that are hallmarks of inflammatory bowel diseases (IBD). Hence, the search for potential therapeutics against ER stress and oxidative stress in intestinal epithelial secretory cells may provide valuable resources for the management of IBD. The aim of the present study was to investigate the effects of BME in ameliorating ER stress in colonic epithelial cells. METHODS: Human colonic adenocarcinoma LS174T cells were used for the assessment of BME effects on colonic epithelial cells in vitro. Cell viability was assessed using trypan blue exclusion and the effect of BME in ameliorating tunicamycin (TM)-induced ER stress was determined by analysing the mRNA expression of the common ER stress markers; ATF6, XBP1, GRP78, CHOP and PERK by quantitative RT-PCR and GRP78 and CHOP by western blot. RESULTS: In the absence of ER stress, BME exhibited no cell toxicity up to 2.0% w/v and no significant effect on the basal mRNA expression of ER stress markers in LS174T cells. In contrast, pre-treatment of LS174T cells with BME followed by induction of ER stress resulted in a significant decrease in mRNA expression of ATF6, XBP1, GRP78, CHOP and PERK and protein expression of GRP78 and CHOP. Co-treatment during induction of ER stress and post- treatment following induction of ER Stress in LS174T cells resulted in a lower but still significant reduction in mRNA expression levels of most ER stress markers. CONCLUSIONS: This is one of the first studies demonstrating the efficacy of BME in reducing expression of ER stress markers in colonic epithelial cells suggesting the potential of BME as a dietary intervention in ameliorating ER stress and oxidation in IBD. Interestingly, while the most significant effect was seen with pre-treatment of cells with BME there was a reduced but still significant effect when co-treated or even post-treated. This suggests that BME may even be effective in modulating ER stress in the face of an existing cell stress environment.
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Estresse do Retículo Endoplasmático/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Doenças Inflamatórias Intestinais/fisiopatologia , Momordica charantia/química , Extratos Vegetais/farmacologia , Substâncias Protetoras/farmacologia , Linhagem Celular Tumoral , Colo/citologia , Colo/efeitos dos fármacos , Colo/metabolismo , Chaperona BiP do Retículo Endoplasmático , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Humanos , Doenças Inflamatórias Intestinais/tratamento farmacológico , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/química , Substâncias Protetoras/química , Fator de Transcrição CHOP/genética , Fator de Transcrição CHOP/metabolismo , Tunicamicina/análise , Tunicamicina/farmacologia , Proteína 1 de Ligação a X-Box/genética , Proteína 1 de Ligação a X-Box/metabolismoRESUMO
BACKGROUND: Endoplasmic reticulum is the major site for protein biosynthesis. Any perturbation in the endoplasmic reticulum will compromise its functions and reduce its efficiency in protein biosynthesis. As a result, misfolded proteins are produced and accumulated in the endoplasmic reticulum. This will result in endoplasmic reticulum stress, which reduces the quantity and quality of the functional protein synthesized from the cell. Besides that, the protein biosynthesis is also highly affected by oxidative stress. Oxidative stress is a condition where the cell has excessive exogenous and endogenous radical oxygen species overwhelming the human body's antioxidant mechanisms. Recent researches have shown that endoplasmic reticulum stress has a strong relationship with oxidative stress and both of them can form a vicious cycle that exacerbates endoplasmic reticulum stress and oxidative stress. Endoplasmic reticulum stress and oxidative stress are harmful to human health since they can disrupt cellular homoeostasis and damage cells. METHOD: This work reported several studies that demonstrate that endoplasmic reticulum stress and oxidative stress have a vital role in the pathogenesis of several diseases, such as diabetes and colitis. RESULTS: Further research is needed to develop the therapeutic strategies that resolve endoplasmic reticulum stress and oxidative stress in order to treat these diseases. CONCLUSION: Currently, Momordicacharantia attracts worldwide attentions due to its various beneficial effects as the functional foods and can possibly help in treating endoplasmic reticulum stress and oxidative stress.