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Obesity is a multifactorial disease and is associated with an increased risk of developing metabolic syndrome and co-morbidities. Dysregulated expansion of the adipose tissue during obesity induces local tissue hypoxia, altered secretory profile of adipokines, cytokines and chemokines, altered profile of local tissue inflammatory cells leading to the development of low-grade chronic inflammation. Low grade chronic inflammation is considered to be the underlying mechanism that increases the risk of developing obesity associated comorbidities. The glucocorticoid induced protein annexin A1 and its N-terminal peptides are anti-inflammatory mediators involved in resolving inflammation. The aim of the current study was to investigate the role of annexin A1 in obesity and associated inflammation. To achieve this aim, the current study analysed data from two feasibility studies in clinical populations: (1) bariatric surgery patients (Pre- and 3 months post-surgery) and (2) Lipodystrophy patients. Plasma annexin A1 levels were increased at 3-months post-surgery compared to pre-surgery (1.2 ± 0.1 ng/mL, n = 19 vs. 1.6 ± 0.1 ng/mL, n = 9, p = 0.009) and positively correlated with adiponectin (p = 0.009, r = 0.468, n = 25). Plasma annexin A1 levels were decreased in patients with lipodystrophy compared to BMI matched controls (0.2 ± 0.1 ng/mL, n = 9 vs. 0.97 ± 0.1 ng/mL, n = 30, p = 0.008), whereas CRP levels were significantly elevated (3.3 ± 1.0 µg/mL, n = 9 vs. 1.4 ± 0.3 µg/mL, n = 31, p = 0.0074). The roles of annexin A1 were explored using an in vitro cell based model (SGBS cells) mimicking the inflammatory status that is observed in obesity. Acute treatment with the annexin A1 N-terminal peptide, AC2-26 differentially regulated gene expression (including PPARA (2.8 ± 0.7-fold, p = 0.0303, n = 3), ADIPOQ (2.0 ± 0.3-fold, p = 0.0073, n = 3), LEP (0.6 ± 0.2-fold, p = 0.0400, n = 3), NAMPT (0.4 ± 0.1-fold, p = 0.0039, n = 3) and RETN (0.1 ± 0.03-fold, p < 0.0001, n = 3) in mature obesogenic adipocytes indicating that annexin A1 may play a protective role in obesity and inflammation. However, this effect may be overshadowed by the continued increase in systemic inflammation associated with rapid tissue expansion in obesity.
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Anexina A1 , Lipodistrofia , Doenças Metabólicas , Anexina A1/farmacologia , Anti-Inflamatórios/farmacologia , Humanos , Inflamação/tratamento farmacológico , Lipodistrofia/tratamento farmacológico , Doenças Metabólicas/tratamento farmacológico , Obesidade/tratamento farmacológico , Peptídeos/farmacologiaRESUMO
BACKGROUND: Intra-regional cultural and linguistic differences are common in low- and middle-income countries. To sensitise undergraduate medical students to the social and contextual determinants of health to achieve the 'health for all' goal, these countries must focus on innovative teaching methods. The early introduction of a Community Orientation Program (COP) as a Community-based Medical Education (CBME) method could be a game changing strategy. In this paper the methods, evaluation, and implication of the COP in an Indian setting are described. METHODS: The curriculum of the COP was developed based on the analysis, design, development, implementation, and evaluation (ADDIE) model for educational intervention. In this learner-centric and supervised educational program, the key aim was to focus on developing students' communication skills, observation power and enhancing their motivation for learning through collaborative learning. To meet the objectives of the COP, a situated learning model under the constructivism theory was adopted. RESULTS: Between 2016 and 2019, 557 students were trained through the COP by visiting more than 1300 households in ten villages. To supplement the students' observations in the community, more than 150 small group discussions, a health education programme for the community and summary presentations were conducted. The students' feedback indicated the need to improve the clinical examinations demonstration quality and increase the number of instruments for clinical examinations. More than 80% of students felt that the program would assist them to improve their communication skills, their understanding of the various socio-demographic factors associated with the common diseases, and it will enable them to respect the local culture during their clinical practice. CONCLUSIONS: Early initiation of the COP as a CBME method in the undergraduate medical curriculum in an Indian setting has shown promising results. Further evidence is required to adopt such a program routinely for under-graduate medical teaching in the low- and middle- income settings.
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Educação de Graduação em Medicina , Educação Médica , Estudantes de Medicina , Currículo , Educação em Saúde , Humanos , MotivaçãoRESUMO
Adipocytes in the breast tumour microenvironment promotes acquired treatment resistance. We used an in vitro adipocyte-conditioned media approach to investigate the direct paracrine effects of adipocyte secretory factors on MDA-MB-231 breast cancer cells treated with doxorubicin to clarify the underlying treatment resistance mechanisms. Cell-viability assays, and Western blots were performed to determine alterations in apoptotic, proliferation and lipid metabolism protein markers. Free fatty acids (FFA) and inflammatory markers in the collected treatment-conditioned media were also quantified. Adipocyte secretory factors increased the cell-viability of doxorubicin-treated cells (p < 0.0001), which did not correspond to apoptosis or proliferation pathways. Adipocyte secretory factors increased the protein expression of hormone-sensitive lipase (p < 0.05) in doxorubicin-treated cells. Adipocyte secretory factors increased the utilization of leptin (p < 0.05) and MCP-1 (p < 0.01) proteins and possibly inhibited release of linoleic acid by doxorubicin-treated cells (treatment-conditioned media FFA profiles). Adipocyte secretory factors induced doxorubicin treatment resistance, by increasing the utilization of inflammatory mediators and inhibiting the release of FFA by doxorubicin-treated cells. This further promotes inflammation and lipid metabolic reprogramming (lipid storage) in the tumour microenvironment, which breast cancer cells use to evade the toxic effects induced by doxorubicin and confers to acquired treatment resistance.
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Metabolismo dos Lipídeos , Neoplasias de Mama Triplo Negativas , Células 3T3-L1 , Adipócitos , Animais , Doxorrubicina/farmacologia , Humanos , Camundongos , Microambiente TumoralRESUMO
PURPOSE: The metabolic syndrome (MetS) is on the rise in Sub-Saharan Africa, attributed to increased and uncontrollable urbanization accompanied by its lifestyle changes. Non-communicable diseases, such as hypertension, diabetes, and obesity, which are components of the (MetS) are also on the increase in Botswana. To date, no study has determined the prevalence of the MetS in the apparently healthy Batswana adults. The objective of the study was to determine the prevalence of the MetS among the 25-65-year-old Batswana residing in urban and neighboring semi-urban areas of Gaborone. PARTICIPANTS AND METHODS: A cross-sectional study was used to collect data from N=794 participants, n=383 men and n=411 women, residing in Gaborone and two surrounding semi-urban areas. Data collected included demographic, anthropometric measurements, blood pressure (BP), blood glucose, triglycerides, high-density lipoprotein cholesterol (HDL-C) and total cholesterol. RESULTS: A high prevalence of 26.8% was reported, with women mostly afflicted (35.0% vs 18.0%). The MetS risk factors found to be common in women were low HDL-C at (50% vs 48.7%) compared to men, while proportions with elevated BP (50.3% vs 39.4%) were prominent in men. The prevalence increased with age, with the oldest age group showing a higher prevalence in both women and men, respectively (55-65 years; 38.5% vs 41.2%). CONCLUSION: An unprecedented high MetS prevalence was revealed among perceived to be healthy Batswana adults, with women at a higher risk. This public health concern creates an opportunity to establish evidence of risk factors, develop guidelines and strategies with appropriate public health measures to prevent and control the MetS.
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Many clinical trials are beginning to assess the effectiveness of compounds known to regulate autophagy in patients receiving anti-cancer chemotherapy. However, autophagy inhibition, through exogenous inhibitors, or activation, through starvation, has revealed conflicting roles in cancer management and chemotherapeutic outcome. This study aimed to assess the effect of amino acid starvation on doxorubicin-treated breast cancer cells by assessing the roles of autophagy and apoptosis. An in vitro breast cancer model consisting of the normal breast epithelial MCF12A and the metastatic breast cancer MDAMB231 cells was used. Apoptotic and autophagic parameters were assessed following doxorubicin treatments, alone or in combination with bafilomycin, ATG5 siRNA or amino acid starvation. Inhibition of autophagy, through ATG5 siRNA or bafilomycin treatment, increased caspase activity and intracellular doxorubicin concentrations in MCF12A and MDAMB231 cells during doxorubicin treatment. While amino acid starvation increased autophagic activity and decreased caspase activity and intracellular doxorubicin concentrations in MCF12A cells, no changes in autophagic parameters or caspase activity were observed in MDAMB231 cells. Our in vivo data showed that 24 h protein starvation during high dose doxorubicin treatment resulted in increased survival of tumor-bearing GFP-LC3 mice. Results from this study suggest that short term starvation during doxorubicin chemotherapy may be a realistic avenue for adjuvant therapy, especially with regards to the protection of non-cancerous cells. More research is however, needed to fully understand the regulation of autophagic flux during starvation.
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Breast cancer cells modulate lipid and fatty acid metabolism to sustain proliferation. The role of adipocytes in cancer treatment efficacy remains, however, to be fully elucidated. We investigated whether diet-induced obesity (DIO) affects the efficacy of doxorubicin treatment in a breast tumor-bearing mouse model. Female C57BL6 mice were fed a high fat or low fat diet for the full duration of the study (12 weeks). After 8 weeks, mice were inoculated with E0771 triple-negative breast cancer cells in the fourth mammary gland to develop breast tumor allographs. Tumor-bearing mice received either vehicle (Hank's balanced salt solution) or doxorubicin (chemotherapy). Plasma inflammatory markers, tumor, and mammary adipose tissue fatty acid composition, as well as protein expression of lipid metabolism markers were determined. The high fat diet (HFD) attenuated the treatment efficacy of doxorubicin. Both leptin and resistin concentrations were significantly increased in the HFD group treated with doxorubicin. Suppressed lipogenesis (decreased stearoyl CoA-desaturase-1) and lipolysis (decreased hormone-sensitive lipase) were observed in mammary adipose tissue of the DIO animals, whereas increased expression was observed in the tumor tissue of doxorubicin treated HFD mice. Obesogenic conditions induced altered tissue fatty acid (FA) compositions, which reduced doxorubicin's treatment efficacy. In mammary adipose tissue breast cancer cells suppressed the storage of FAs, thereby increasing the availability of free FAs and favored inflammation under obesogenic conditions.
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Parkinson's disease (PD) is a well-known neurodegenerative disease with a strong association established with systemic inflammation. Recently, the role of the gingipain protease group from Porphyromonas gingivalis was implicated in Alzheimer's disease and here we present evidence, using a fluorescent antibody to detect gingipain R1 (RgpA), of its presence in a PD population. To further elucidate the action of this gingipain, as well as the action of the lipopolysaccharide (LPS) from P. gingivalis, low concentrations of recombinant RgpA and LPS were added to purified fluorescent fibrinogen. We also substantiate previous findings regarding PD by emphasizing the presence of systemic inflammation via multiplex cytokine analysis, and demonstrate hypercoagulation using thromboelastography (TEG), confocal and electron microscopy. Biomarker analysis confirmed significantly increased levels of circulating proinflammatory cytokines. In our PD and control blood analysis, our results show increased hypercoagulation, the presence of amyloid formation in plasma, and profound ultrastructural changes to platelets. Our laboratory analysis of purified fibrinogen with added RgpA, and/or LPS, showed preliminary data with regards to the actions of the protease and the bacterial membrane inflammagen on plasma proteins, to better understand the nature of established PD.
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BACKGROUND: The global burden of type 2 diabetes mellitus (T2DM), together with the presence of cardiovascular risk in this population, is reaching pandemic levels. A prominent feature of T2DM is chronic and systemic inflammation, with the accompanying presence of circulating and dysregulated inflammatory biomarkers; which in turn is associated with abnormal clot formation. METHODS: Here, we investigate the correlation between abnormal blood clotting, using thromboelastography (TEG), clot ultrastructure using scanning electron microscopy (SEM) and the presence of a dysregulated inflammatory cytokine profile, by examining various circulating biomarkers. RESULTS: Our results show that many biomarkers, across TEG, cytokine and lipid groups, were greatly dysregulated in the T2DM sample. Furthermore, our T2DM sample's coagulation profiles were significantly more hypercoagulable when compared to our heathy sample, and ultrastructural analysis confirmed a matted and denser clot structure in the T2DM sample. CONCLUSIONS: We suggest that dysregulated circulating molecules may in part be responsible for a hypercoagulable state and vascular dysfunction in the T2DM sample. We propose further that a personalized approach could be of great value when planning treatment and tracking the patient health status after embarking on a treatment regimes, and that looking to novel inflammatory and vascular biomarkers might be crucial.
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Coagulação Sanguínea , Citocinas/sangue , Diabetes Mellitus Tipo 2/complicações , Mediadores da Inflamação/sangue , Trombofilia/etiologia , Biomarcadores/sangue , Estudos de Casos e Controles , Estudos Transversais , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/diagnóstico , Feminino , Humanos , Masculino , Microscopia Eletrônica de Varredura , Pessoa de Meia-Idade , Tromboelastografia , Trombofilia/complicações , Trombofilia/diagnósticoRESUMO
Complex associations exist between inflammation and thrombosis, with the inflammatory state tending to promote coagulation. Fibrinogen, an acute phase protein, has been shown to interact with the amyloidogenic ß-amyloid protein of Alzheimer's disease. However, little is known about the association between fibrinogen and serum amyloid A (SAA), a highly fibrillogenic protein that is one of the most dramatically changing acute phase reactants in the circulation. To study the role of SAA in coagulation and thrombosis, in vitro experiments were performed where purified human SAA, in concentrations resembling a modest acute phase response, was added to platelet-poor plasma (PPP) and whole blood (WB), as well as purified and fluorescently labelled fibrinogen. Results from thromboelastography (TEG) suggest that SAA causes atypical coagulation with a fibrin(ogen)-mediated increase in coagulation, but a decreased platelet/fibrin(ogen) interaction. In WB scanning electron microscopy analysis, SAA mediated red blood cell (RBC) agglutination, platelet activation and clumping, but not platelet spreading. Following clot formation in PPP, the presence of SAA increased amyloid formation of fibrin(ogen) as determined both with auto-fluorescence and with fluorogenic amyloid markers, under confocal microcopy. SAA also binds to fibrinogen, as determined with a fluorescent-labelled SAA antibody and correlative light electron microscopy (CLEM). The data presented here indicate that SAA can affect coagulation by inducing amyloid formation in fibrin(ogen), as well as by propelling platelets to a more prothrombotic state. The discovery of these multiple and complex effects of SAA on coagulation invite further mechanistic analyses.
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Reação de Fase Aguda/metabolismo , Amiloide/metabolismo , Plaquetas/metabolismo , Fibrinogênio/metabolismo , Proteína Amiloide A Sérica/fisiologia , Trombose/metabolismo , Adulto , Aglutinação , Doença de Alzheimer/metabolismo , Coagulação Sanguínea , Plaquetas/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Ativação Plaquetária , Agregação Plaquetária , Ligação ProteicaRESUMO
Although rollout of combined antiretroviral treatment (cART) has blunted human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) onset, there is increased development of cardiovascular diseases (CVDs) in HIV-infected individuals. While most HIV-infected individuals on cART achieve viral suppression, this may not necessarily result in complete immunological recovery. This study therefore evaluated T-cell-mediated changes and coagulation markers in HIV-positive individuals to ascertain their potential to increase CVD risk. Eighty participants were recruited (Worcester, South Africa), and fasted blood was collected to evaluate: 1) immune activation (CD38 expression on CD4+ and CD8+ T cells) and thrombus formation [tissue factor (CD142)] on CD4+ and CD8+ T cells; 2) monocyte subpopulations (nonclassical, intermediate, and classical); and 3) classical regulatory T (Treg) cells with activation markers [glycoprotein A repetitions predominant (GARP) and special AT-rich sequence-binding protein 1 (SATB-1)]. High- and low-density lipoprotein subclasses (Lipoprint) were also determined. This study revealed four key findings for HIV-positive patients: 1) coexpression of the CD142 coagulation marker together with immune activation on both CD4+ and CD8+ T cells during chronic infection stages; 2) Treg cell activation and upregulated GARP and SATB-1 contributing to Treg dysfunction in chronic HIV; 3) proatherogenic monocyte subset expansion with significant correlation between T-cell activation and macrophage activation (marker: CD163); and 4) significant correlation between immune activation and lipid subclasses, revealing crucial changes that can be missed by traditional lipid marker assessments (LDL and HDL). These data also implicate lipopolysaccharide-binding protein as a crucial link between immune activation, lipid alterations, and increased CVD risk. NEW & NOTEWORTHY With combined antiretroviral treatment rollout, HIV-AIDS patients are increasingly associated with cardiovascular diseases onset. This study demonstrated the significant interplay between adaptive immune cell activation and monocyte/macrophage markers in especially HIV-positive individuals with virological failure and on second line treatment. Our data also show a unique link between immune activation and lipid subclass alterations, revealing important changes that can be missed by traditional lipid marker assessments (e.g., LDL and HDL).
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Coagulação Sanguínea , Doenças Cardiovasculares/etiologia , Infecções por HIV/complicações , Lipídeos/sangue , Ativação Linfocitária , Monócitos/imunologia , Subpopulações de Linfócitos T/imunologia , Adulto , Fármacos Anti-HIV/uso terapêutico , Antígenos CD/sangue , Antígenos de Diferenciação Mielomonocítica/sangue , Biomarcadores/sangue , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/imunologia , Estudos de Casos e Controles , Proliferação de Células , Estudos Transversais , Feminino , Fatores de Transcrição Forkhead/sangue , Infecções por HIV/sangue , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Humanos , Ativação de Macrófagos , Masculino , Proteínas de Ligação à Região de Interação com a Matriz/sangue , Proteínas de Membrana/sangue , Pessoa de Meia-Idade , Monócitos/metabolismo , Receptores de Superfície Celular/sangue , Fatores de Risco , Subpopulações de Linfócitos T/metabolismo , Tromboplastina/metabolismoRESUMO
Globally, breast cancer continues to be a major concern in women's health. Lifestyle related risk factors, specifically excess adipose tissue (adiposity) has reached epidemic proportions and has been identified as a major risk factor in the development of breast cancer. Dysfunctional adipose tissue has evoked research focusing on its association with metabolic-related conditions, breast cancer risk and progression. Adipose dysfunction in coordination with immune cells and inflammation, are responsible for accelerated cell growth and survival of cancer cells. Recently, evidence also implicates adiposity as a potential risk factor for chemotherapy resistance. Chemotherapeutic agents have been shown to negatively impact adipose tissue. Since adipose tissue is a major storage site for fatty acids, it is not unlikely that these negative effects may disrupt adipose tissue homeostasis. It is therefore argued that fatty acid composition may be altered due to the chemotherapeutic pharmacokinetics, which in turn could have severe health related outcomes. The underlying molecular mechanisms elucidating the effects of fatty acid composition in adiposity-linked drug resistance are still unclear and under explored. This review focuses on the potential role of adiposity in breast cancer and specifically emphasizes the role of fatty acids in cancer progression and treatment resistance.
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Adiposidade , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Ácidos Graxos/metabolismo , Tecido Adiposo/metabolismo , Antibióticos Antineoplásicos/metabolismo , Antibióticos Antineoplásicos/uso terapêutico , Neoplasias da Mama/patologia , Carcinogênese/metabolismo , Membrana Celular/metabolismo , Doxorrubicina/metabolismo , Doxorrubicina/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Inflamação/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Obesidade/metabolismo , Fatores de RiscoRESUMO
BACKGROUND: A strong correlation exists between type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD), with CVD and the presence of atherosclerosis being the prevailing cause of morbidity and mortality in diabetic populations. T2DM is accompanied by various coagulopathies, including anomalous clot formation or amyloid fibrin(ogen), the presence of dysregulated inflammatory molecules. Platelets are intimately involved in thrombus formation and particularly vulnerable to inflammatory cytokines. METHODS: The aim of this current study was therefore to assess whole blood (hyper)coagulability, platelet ultrastructure and receptor expression, as well as the levels of IL-1ß, IL-6, IL-8 and sP-selectin in healthy and diabetic individuals. Platelet morphology was assessed through scanning electron microscopy (SEM), while assessment of GPIIb/IIIa receptor expression was performed with confocal microscopy and flow cytometry with the addition of FITC-PAC-1 and CD41-PE antibodies. IL-1ß, IL-6 and IL-8 and sP-selectin levels were assessed using a multiplex assay. RESULTS: In T2DM there is significant upregulation of circulating inflammatory markers, hypercoagulation and platelet activation, with increased GPIIb/IIIa receptor expression, as seen with flow cytometry and confocal microscopy. Analyses showed that these receptors were additionally shed onto microparticles, which was confirmed with SEM. CONCLUSIONS: Cumulatively, this provides mechanistic evidence that pathological states of platelets together with amyloid fibrin(ogen) in T2DM, might underpin an increased risk for cardiovascular events.
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Coagulação Sanguínea , Plaquetas/metabolismo , Micropartículas Derivadas de Células/metabolismo , Diabetes Mellitus Tipo 2/sangue , Ativação Plaquetária , Trombofilia/sangue , Trombose/sangue , Idoso , Biomarcadores/sangue , Fatores de Coagulação Sanguínea/análise , Plaquetas/ultraestrutura , Estudos de Casos e Controles , Micropartículas Derivadas de Células/ultraestrutura , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/diagnóstico , Feminino , Humanos , Mediadores da Inflamação/sangue , Interleucinas/sangue , Masculino , Pessoa de Meia-Idade , Selectina-P/sangue , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/análise , Trombofilia/diagnóstico , Trombofilia/etiologia , Trombose/diagnóstico , Trombose/etiologiaRESUMO
BACKGROUND: Sufficient evidence associate body shape to detrimental lifestyle diseases including the metabolic syndrome (MetS). The prevalence of the MetS, as well as effects of the MetS and body shape on body composition, insulin-like growth factor-1 (IGF-1), C-reactive protein (CRP) and sex hormone parameters were investigated in a female farm worker population in the Western Cape. METHODS: Women between the ages of 20-60 years were classified according to the International Diabetes Federation's definition of the MetS. Assessments included body shape (android/gynoid), blood pressure, anthropometric, bioelectrical impedance analyses and blood analyses for fasting glucose and insulin, lipid profile, IGF-1, CRP, and sex hormone parameters. RESULTS: The prevalence of the MetS was 52%, with abdominal obesity 68.8%, hypertension 66.4% and low high density lipoprotein-cholesterol (HDL-c) levels (64.1%) being the more prevalent MetS risk factors. The MetS, irrespective of body shape, was found to be associated with body mass index (p < 0.01), fat mass (%) (p < 0.01), waist circumference (p < 0.001), HDL-c (p < 0.001), systolic blood pressure (p < 0.05) and diastolic blood pressure (p < 0.01). No significant differences were observed for IGF-1, CRP and sex hormone parameters. CONCLUSION: The prevalence of the MetS and its individual risk factors were found to be significantly high in this female farm worker population. Additionally, the study showed that the MetS, body shape and/or both could predict differences in body composition, physiological and biochemical parameters in women.
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Tamanho Corporal , Fazendeiros/estatística & dados numéricos , Disparidades nos Níveis de Saúde , Síndrome Metabólica/epidemiologia , Mulheres Trabalhadoras/estatística & dados numéricos , Adulto , Feminino , Indicadores Básicos de Saúde , Humanos , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Adulto JovemRESUMO
Excess adipose tissue is a hallmark of an overweight and/or obese state as well as a primary risk factor for breast cancer development and progression. In an overweight/obese state adipose tissue becomes dysfunctional due to rapid hypertrophy, hyperplasia, and immune cell infiltration which is associated with sustained low-grade inflammation originating from dysfunctional adipokine synthesis. Evidence also supports the role of excess adipose tissue (overweight/obesity) as a casual factor for the development of chemotherapeutic drug resistance. Obesity-mediated effects/modifications may contribute to chemotherapeutic drug resistance by altering drug pharmacokinetics, inducing chronic inflammation, as well as altering tumor-associated adipocyte adipokine secretion. Adipocytes in the breast tumor microenvironment enhance breast tumor cell survival and decrease the efficacy of chemotherapeutic agents, resulting in chemotherapeutic resistance. A well-know chemotherapeutic agent, doxorubicin, has shown to negatively impact adipose tissue homeostasis, affecting adipose tissue/adipocyte functionality and storage. Here, it is implied that doxorubicin disrupts adipose tissue homeostasis affecting the functionality of adipose tissue/adipocytes. Although evidence on the effects of doxorubicin on adipose tissue/adipocytes under obesogenic conditions are lacking, this narrative review explores the potential role of obesity in breast cancer progression and treatment resistance with inflammation as an underlying mechanism.
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Since cancer shares the same molecular machinery as the host, most therapeutic interventions that aim to target cancer would inadvertently also adversely affect the host. In addition, cancer continuously evolves, streamlining its host-derived genome for a new single-celled existence. In particular, short-term clinical success observed with most antineoplastic therapies directly relate to the fact that cancer is constantly evolving. However, the clonal evolution of cancer occasionally also render cancer cells uniquely susceptible to therapeutic interventions, as is exemplified by the clinical relevance of synthetic lethality. Synthetic lethality describes a situation where the simultaneous loss of function in two genes results in lethality, but where a loss of function in either single gene is tolerated. This observation suggests that the evolution of cancer, usually seen as a major clinical challenge, may also afford a key opportunity in lowering on-target toxicities accosted with chemotherapy. As an example, by subjecting cancer to specific selection regimes, cancer can in effect be placed on evolutionary trajectories leading to the development of "targetable" phenotypes such as synthetic lethal interactions. However, such a selection regime would have to overcome a range of obstacles such as on-target toxicity and the selection of an evolvable trait. Since the majority of cancer evolution manifests as a loss of function, we suggest that the induction of auxotrophic phenotypes (i.e., where an organism lose the ability to synthesize specific organic compounds required for growth and thus become dependent on it from dietary sources) may represent an attractive therapeutic option. As an example, animals can obtain vitamin C either by de novo synthesis or from their diet. However, since the maintenance of synthetic pathways is costly, such pathways are often lost if no longer necessary, resulting in the organism being auxotrophic toward the dietary compound. Similarly, increasing the maintenance cost of a redundant pathway in cancer cells is likely to select for clones that have lost such a redundant pathway. Inhibition of a pathway, while supporting the activity of a compensating pathway, may thus induce auxotrophism in cancer cells but not in genomic stable host cells.
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BACKGROUND: In South Africa, not much is known about MetS in farm working communities. This study aimed to describe the prevalence of the MetS in a farm working population from the Boland winelands district of the Western Cape, South Africa. METHODS: A cross-sectional study was followed among farm workers (aged 20-60 years) from surrounding wine estates. The questionnaires used described socio-demographic status, ethnic background, alcohol consumption, smoking, exercise and daily medication. Anthropometric assessments were performed and blood pressure measurements taken prior to blood sampling for serum insulin, glucose and fasting lipogram profiles. RESULTS: The prevalence of the MetS was higher in women (46.3 vs 29.3%). Both men and women in the MetS group had a significantly higher waist circumferences (WC; p < 0.001 for both), whilst higher glucose levels were only significantly higher in the women (p < 0.001). Correlations showed significant differences between body mass index (BMI), WC and waist to hip ratio (W:H) and the different MetS risk factors. CONCLUSIONS: The female population in this study showed higher prevalence rates for the individual risk factors and the MetS overall. There is an urgent need to develop culturally sensitive health promotion programs addressing risk factors for metabolic syndrome among farm workers.
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Fazendeiros/estatística & dados numéricos , Síndrome Metabólica/epidemiologia , Adulto , Fatores Etários , Consumo de Bebidas Alcoólicas/epidemiologia , Índice de Massa Corporal , Estudos Transversais , Etnicidade/estatística & dados numéricos , Exercício Físico , Fazendas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Fatores Sexuais , Fumar/epidemiologia , Fatores Socioeconômicos , África do Sul/epidemiologia , Inquéritos e Questionários , Adulto JovemRESUMO
During an infection, expansion of immune cells, assembly of antibodies, and the induction of a febrile response collectively place continual metabolic strain on the host. These considerations also provide a rationale for nutritional support in critically ill patients. Yet, results from clinical and preclinical studies indicate that aggressive nutritional support does not always benefit patients and may occasionally be detrimental. Moreover, both vertebrates and invertebrates exhibit a decrease in appetite during an infection, indicating that such sickness-associated anorexia (SAA) is evolutionarily conserved. It also suggests that SAA performs a vital function during an infection. We review evidence signifying that SAA may present a mechanism by which autophagic flux is upregulated systemically. A decrease in serum amino acids during an infection promotes autophagy not only in immune cells, but also in nonimmune cells. Similarly, bile acids reabsorbed postprandially inhibit hepatic autophagy by binding to farnesoid X receptors, indicating that SAA may be an attempt to conserve autophagy. In addition, augmented autophagic responses may play a critical role in clearing pathogens (xenophagy), in the presentation of epitopes in nonprovisional antigen presenting cells and the removal of damaged proteins and organelles. Collectively, these observations suggest that some patients might benefit from permissive underfeeding.
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Anorexia/fisiopatologia , Apetite , Estado Terminal/terapia , Terapia Nutricional/métodos , Aminoácidos/sangue , Aminoácidos/química , Animais , Ingestão de Energia , Epitopos/química , Jejum , Humanos , Sistema Imunitário , Necessidades Nutricionais , Estado Nutricional , Prevalência , Receptores Citoplasmáticos e Nucleares/metabolismo , InaniçãoRESUMO
Activation of the immune system is metabolically costly, yet a hallmark of an infection is a reduction in appetite with a subsequent reduction in metabolite provision. What is the functional value of decreasing nutrient intake when an infection imposes large demands on metabolic parameters? Here, we propose that sickness-associated anorexia (SAA) upregulates the ancient process of autophagy systemically, thereby profoundly controlling not only immune- but also nonimmune-competent cells. This allows an advanced impact on the resolution of an infection through direct pathogen killing, enhancement of epitope presentation and the contribution toward the clearance of noxious factors. By rendering a 'free meal,' autophagy is thus most fundamentally harnessed during an anorexic response in order to promote both host tolerance and resistance. These findings strongly suggest a reassessment of numerous SAA-related clinical applications and a re-evaluation of current efforts in patient care.
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Anorexia/patologia , Autofagia , Aminoácidos/sangue , Anorexia/sangue , Humanos , Fígado/patologia , Modelos BiológicosRESUMO
Immunologists have recently taken note of the fact that a host not only resists infection, but also exhibits a capacity to manage the pathology associated with such infection - a concept referred to as tolerance. Here we explore how the tolerance/resistance (T/R) framework can be implemented within an oncological context and explore a number of implications. In particular, the T/R framework distinguishes between pathology manifesting from extensive tumor burden, versus cancers intrinsically expressing a more pathogenic phenotype. Consequently, the T/R framework provides novel methodology in studying the nature of cancer pathology and for marker identification. Additionally, this framework may aid in redefining the therapeutic end point under suitable circumstances: establishing cancer as a chronic, manageable disease.
Assuntos
Tolerância Imunológica/imunologia , Neoplasias/imunologia , Virulência/imunologia , Animais , Humanos , CamundongosRESUMO
Although numerous studies have shown that certain long chain fatty acids can induce apoptosis in cancer cells, the molecular mechanisms for this phenomenon are still poorly elucidated. The phosphoinositide 3-kinase (PI3-kinase) signaling pathway plays a pivotal role in the regulation of cell growth and can also contribute to tumorigenesis and cancer progression. The aims of the present study were three fold: (i) to investigate the potential chemopreventative/antiproliferative effect of various fatty acids in colon cancer cells (CaCo-2 cells) and normal colon epithelium cells (NCM460 cells); (ii) to investigate the mechanisms by which incubation with various fatty acids influences the PI3-kinase pathway in CaCo-2 cells; and (iii) to evaluate apoptosis in our cell model. Although all the fatty acids increased the viability of normal (NCM460) cells, only docosahexaenoic acid (DHA) significantly reduced cell viability and induced apoptosis in the cancer (CaCo-2) cells. Our results indicate that DHA is an effective chemotherapeutic agent to induce apoptosis in cancer cells and that this effect is mediated by the PI3-kinase signaling pathway.