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Appetite problem in cancer patients: Pathophysiology, diagnosis, and treatment. Cancer Treat Res Commun 2021; 27:100336. [PMID: 33607591 DOI: 10.1016/j.ctarc.2021.100336] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 02/01/2021] [Accepted: 02/06/2021] [Indexed: 01/02/2023]
Abstract
AIM This study aims to review the current evidence regarding appetite problem in cancer patients, mainly focusing on pathophysiology, diagnosis, and treatment. INTRODUCTION Anorexia is the common symptom of malnutrition in cancer patients. Recently, the understanding of the pathophysiological mechanism of the appetite problem in cancer patients has been increasing that give impact to rigorous research to find the therapies for improving appetite in cancer patients. DISCUSSION The development of anorexia in cancer patients is a complex process that involves many cytokines, receptors, chemical mediators/substances, hormones, and peptides. Growth and differentiation factor-15 (GDF-15) and toll-like receptor (TLR-4) have recently been found to be implicated in the pathogenesis of anorexia. To help diagnose the appetite problem in cancer patients, several questionnaires can be used, starting from well-known questionnaires such as Functional Assessment of Anorexia Cachexia Therapy (FAACT), Visual Analog Scale (VAS), European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC-QLQ30). Several drugs with different mechanisms of action have been studied to help in improving appetite in cancer patients. New repurposed agents such as anamorelin, mirtazapine, thalidomide, and eicosapentaenoic acid (EPA) have shown a beneficial effect in improving appetite and quality of life in cancer patients, however more phase 3 clinical trial studies is still needed. CONCLUSION The pathophysiology of appetite problems in cancer patients is a complex process that involves many factors. Several drugs that target those factors have been studied, however more phase 3 clinical trial studies are needed to confirm the findings from previous studies.
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Wyart E, Bindels LB, Mina E, Menga A, Stanga S, Porporato PE. Cachexia, a Systemic Disease beyond Muscle Atrophy. Int J Mol Sci 2020; 21:E8592. [PMID: 33202621 PMCID: PMC7696729 DOI: 10.3390/ijms21228592] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 11/06/2020] [Accepted: 11/12/2020] [Indexed: 02/06/2023] Open
Abstract
Cachexia is a complication of dismal prognosis, which often represents the last step of several chronic diseases. For this reason, the comprehension of the molecular drivers of such a condition is crucial for the development of management approaches. Importantly, cachexia is a syndrome affecting various organs, which often results in systemic complications. To date, the majority of the research on cachexia has been focused on skeletal muscle, muscle atrophy being a pivotal cause of weight loss and the major feature associated with the steep reduction in quality of life. Nevertheless, defining the impact of cachexia on other organs is essential to properly comprehend the complexity of such a condition and potentially develop novel therapeutic approaches.
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Affiliation(s)
- Elisabeth Wyart
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, 10126 Turin, Italy; (E.W.); (E.M.); (A.M.)
| | - Laure B. Bindels
- Metabolism and Nutrition Research Group, Louvain Drug Research Institute, UCLouvain, Université Catholique de Louvain, 1200 Brussels, Belgium;
| | - Erica Mina
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, 10126 Turin, Italy; (E.W.); (E.M.); (A.M.)
| | - Alessio Menga
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, 10126 Turin, Italy; (E.W.); (E.M.); (A.M.)
| | - Serena Stanga
- Neuroscience Institute Cavalieri Ottolenghi, 10043 Orbassano (TO), Department of Neuroscience Rita Levi Montalcini, University of Turin, 10126 Turin, Italy;
| | - Paolo E. Porporato
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, 10126 Turin, Italy; (E.W.); (E.M.); (A.M.)
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Ezeoke CC, Morley JE. Pathophysiology of anorexia in the cancer cachexia syndrome. J Cachexia Sarcopenia Muscle 2015; 6:287-302. [PMID: 26675762 PMCID: PMC4670736 DOI: 10.1002/jcsm.12059] [Citation(s) in RCA: 134] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 06/11/2015] [Accepted: 06/22/2015] [Indexed: 12/20/2022] Open
Abstract
Anorexia is commonly present in persons with cancer and a major component of cancer cachexia. There are multiple causes of anorexia in cancer. Peripherally, these can be due to (i) substances released from or by the tumour, e.g. pro-inflammatory cytokines, lactate, and parathormone-related peptide; (ii) tumours causing dysphagia or altering gut function; (iii) tumours altering nutrients, e.g. zinc deficiency; (iv) tumours causing hypoxia; (v) increased peripheral tryptophan leading to increased central serotonin; or (vi) alterations of release of peripheral hormones that alter feeding, e.g. peptide tyrosine tyrosine and ghrelin. Central effects include depression and pain, decreasing the desire to eat. Within the central nervous system, tumours create multiple alterations in neurotransmitters, neuropeptides, and prostaglandins that modulate feeding. Many of these neurotransmitters appear to produce their anorectic effects through the adenosine monophosphate kinase/methylmalonyl coenzyme A/fatty acid system in the hypothalamus. Dynamin is a guanosine triphosphatase that is responsible for internalization of melanocortin 4 receptors and prostaglandin receptors. Dynamin is up-regulated in a mouse model of cancer anorexia. A number of drugs, e.g. megestrol acetate, cannabinoids, and ghrelin agonists, have been shown to have some ability to be orexigenic in cancer patients.
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Affiliation(s)
- Chukwuemeka Charles Ezeoke
- United States Navy Medical Corps and PGY-2, Internal Medicine Residency, Saint Louis University HospitalSt. Louis, MO, USA
| | - John E Morley
- Division of Geriatrics, Saint Louis University School of Medicine1402 S. Grand Blvd., M238, St. Louis, MO, 63104, USA
- Division of Endocrinology, Saint Louis University School of MedicineSt. Louis, MO, USA
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Molfino A, Gioia G, Fanelli FR, Laviano A. Contribution of Neuroinflammation to the Pathogenesis of Cancer Cachexia. Mediators Inflamm 2015; 2015:801685. [PMID: 26504362 PMCID: PMC4609516 DOI: 10.1155/2015/801685] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 06/10/2015] [Indexed: 11/18/2022] Open
Abstract
Inflammation characterizes the course of acute and chronic diseases and is largely responsible for the metabolic and behavioral changes occurring during the clinical journey of patients. Robust data indicate that, during cancer, functional modifications within brain areas regulating energy homeostasis contribute to the onset of anorexia, reduced food intake, and increased catabolism of muscle mass and adipose tissue. In particular, functional changes are associated with increased hypothalamic concentration of proinflammatory cytokines, which suggests that neuroinflammation may represent the adaptive response of the brain to peripheral challenges, including tumor growth. Within this conceptual framework, the vagus nerve appears to be involved in conveying alert signals to the hypothalamus, whereas hypothalamic serotonin appears to contribute to triggering catabolic signals.
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Affiliation(s)
- Alessio Molfino
- Department of Clinical Medicine, Sapienza University of Rome, Viale del Policlinico 155, 00161 Rome, Italy
| | - Gianfranco Gioia
- Department of Clinical Medicine, Sapienza University of Rome, Viale del Policlinico 155, 00161 Rome, Italy
| | - Filippo Rossi Fanelli
- Department of Clinical Medicine, Sapienza University of Rome, Viale del Policlinico 155, 00161 Rome, Italy
| | - Alessandro Laviano
- Department of Clinical Medicine, Sapienza University of Rome, Viale del Policlinico 155, 00161 Rome, Italy
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The neuropeptide Y system: Pathophysiological and therapeutic implications in obesity and cancer. Pharmacol Ther 2011; 131:91-113. [DOI: 10.1016/j.pharmthera.2011.03.011] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2011] [Accepted: 03/07/2011] [Indexed: 12/28/2022]
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Laviano A. Michelangelo, the Sistine Chapel and the “secret” of cancer cachexia. SOUTH AFRICAN JOURNAL OF CLINICAL NUTRITION 2010. [DOI: 10.1080/16070658.2010.11734325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Liu Q, Wong-Riley MTT. Postnatal changes in the expressions of serotonin 1A, 1B, and 2A receptors in ten brain stem nuclei of the rat: implication for a sensitive period. Neuroscience 2009; 165:61-78. [PMID: 19800944 DOI: 10.1016/j.neuroscience.2009.09.078] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Revised: 09/25/2009] [Accepted: 09/28/2009] [Indexed: 01/08/2023]
Abstract
A critical period in respiratory network development occurs in the rat around postnatal days (P) 12-13, when abrupt neurochemical, metabolic, and physiological changes were evident. As serotonin and its receptors are involved in respiratory modulation, and serotonergic abnormality is implicated in sudden infant death syndrome, we hypothesized that 5-HT receptors are significantly downregulated during the critical period. This was documented recently for 5-HT(2A)R in several respiratory nuclei. The present study represents a comprehensive analysis of postnatal development of 5-HT(1A)R and 5-HT(1B)R in 10 brain stem nuclei and 5-HT(2A)R in six nuclei not previously examined. Optical densitometric analysis of immunohistochemically-reacted neurons from P2 to P21 indicated four developmental patterns of expression: (1) Pattern I: a high level of expression at P2-P11, an abrupt and significant reduction at P12, followed by a plateau until P21 (5-HT(1A)R and 5-HT(1B)R in raphé magnus [RM], raphé obscurus [ROb], raphé pallidus [RP], pre-Bötzinger complex [PBC], nucleus ambiguus [Amb], and hypoglossal nucleus [XII; 5-HT(1A)R only]). (2) Pattern II: a high level at P2-P9, a gradual decline from P9 to P12, followed by a plateau until P21 (5-HT(1A)R and 5-HT(1B)R in the retrotrapezoid nucleus (RTN)/parafacial respiratory group (pFRG)). (3) Pattern III: a high level at P2-P11, followed by a gradual decline until P21 (5-HT(1A)R in the ventrolateral subnucleus of solitary tract nucleus [NTS(VL)] and the non-respiratory cuneate nucleus [CN]). (4) Pattern IV: a relatively constant level maintained from P2 to P21 (5-HT(1A)R in the commissural subnucleus of solitary tract nucleus (NTS(COM)); 5-HT(1B)R in XII, NTS(VL), NTS(COM), and CN; and 5-HT(2A)R in RM, ROb, RP, RTN/pFRG, NTS(VL), and NTS(COM)). Thus, a significant reduction in the expression of 5-HT(1A)R, 5-HT(1B)R, and 5-HT(2A)R in multiple respiratory-related nuclei at P12 is consistent with reduced serotonergic transmission during the critical period, thereby rendering the animals less able to respond adequately to ventilatory distress.
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Affiliation(s)
- Q Liu
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, 53226, USA
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Laviano A, Meguid MM, Cascino A, Molfino A, Rossi Fanelli F. Tryptophan in wasting diseases: at the crossing between immune function and behaviour. Curr Opin Clin Nutr Metab Care 2009; 12:392-7. [PMID: 19465846 DOI: 10.1097/mco.0b013e32832b73af] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
PURPOSE OF REVIEW Wasting diseases are characterized by progressive deterioration of nutritional status that negatively influences patients' outcome. The better understanding of the pathogenic mechanisms of wasting may lead to effective therapies. Tryptophan metabolism has unique features suggesting a critical role in influencing human metabolism under normal and pathological conditions. RECENT FINDINGS During disease, inflammatory response favours the local depletion of the essential amino acid tryptophan, thereby inhibiting cellular proliferation. Tryptophan depletion may also mediate immunotolerance to foreign antigens. In contrast, brain accumulation of tryptophan contributes to wasting by increasing oxidative stress and hypothalamic serotonin neurotransmission, and thereby triggering the onset of sickness behaviour followed by depressive-like behaviour. SUMMARY Tryptophan metabolism is critical in mediating a number of important biological responses. Restoring tryptophan metabolism may well result in enhanced recovery from disease.
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Affiliation(s)
- Alessandro Laviano
- Department of Clinical Medicine, Sapienza University of Rome, Rome, Italy.
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Laviano A, Inui A, Marks DL, Meguid MM, Pichard C, Rossi Fanelli F, Seelaender M. Neural control of the anorexia-cachexia syndrome. Am J Physiol Endocrinol Metab 2008; 295:E1000-8. [PMID: 18713954 DOI: 10.1152/ajpendo.90252.2008] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The anorexia-cachexia syndrome is a debilitating clinical condition characterizing the course of chronic diseases, which heavily impacts on patients' morbidity and quality of life, ultimately accelerating death. The pathogenesis is multifactorial and reflects the complexity and redundancy of the mechanisms controlling energy homeostasis under physiological conditions. Accumulating evidence indicates that, during disease, disturbances of the hypothalamic pathways controlling energy homeostasis occur, leading to profound metabolic changes in peripheral tissues. In particular, the hypothalamic melanocortin system does not respond appropriately to peripheral inputs, and its activity is diverted largely toward the promotion of catabolic stimuli (i.e., reduced energy intake, increased energy expenditure, possibly increased muscle proteolysis, and adipose tissue loss). Hypothalamic proinflammatory cytokines and serotonin, among other factors, are key in triggering hypothalamic resistance. These catabolic effects represent the central response to peripheral challenges (i.e., growing tumor, renal, cardiac failure, disrupted hepatic metabolism) that are likely sensed by the brain through the vagus nerve. Also, disease-induced changes in fatty acid oxidation within hypothalamic neurons may contribute to the dysfunction of the hypothalamic melanocortin system. Ultimately, sympathetic outflow mediates, at least in part, the metabolic changes in peripheral tissues. Other factors are likely involved in the pathogenesis of the anorexia-cachexia syndrome, and their role is currently being elucidated. However, available evidence shows that the constellation of symptoms characterizing this syndrome should be considered, at least in part, as different phenotypes of common neurochemical/metabolic alterations in the presence of a chronic inflammatory state.
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Affiliation(s)
- Alessandro Laviano
- Department of Clinical Medicine, Sapienza University of Rome, Rome, Italy.
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NPY and brain monoamines in the pathogenesis of cancer anorexia. Nutrition 2008; 24:802-5. [DOI: 10.1016/j.nut.2008.06.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2008] [Revised: 06/03/2008] [Accepted: 06/09/2008] [Indexed: 11/17/2022]
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Shinozaki T, Kimura M, Hosoyamada M, Shibasaki T. Fluvoxamine Inhibits Weight Gain and Food Intake in Food Restricted Hyperphagic Wistar Rats. Biol Pharm Bull 2008; 31:2250-4. [DOI: 10.1248/bpb.31.2250] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
| | - Masaki Kimura
- Division of Pharmacotherapeutics, Faculty of Pharmacy, Keio University
| | - Makoto Hosoyamada
- Division of Pharmacotherapeutics, Faculty of Pharmacy, Keio University
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Jacobs C, Van Den Broeck W, Simoens P. Neurons expressing serotonin-1B receptor in the basolateral nuclear group of the amygdala in normally behaving and aggressive dogs. Brain Res 2007; 1136:102-9. [PMID: 17223093 DOI: 10.1016/j.brainres.2006.11.096] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2006] [Revised: 11/17/2006] [Accepted: 11/27/2006] [Indexed: 01/09/2023]
Abstract
The present study aimed to quantify neurons expressing the serotonin-1B receptor and evaluate numerical differences in normally behaving and pathologically aggressive dogs in order to assess whether the serotonin-1B receptor is involved in pathological canine aggression. Because previous studies have reported structural alterations in the basolateral nuclear group (BNG) of the amygdaloid body of aggressive dogs, this structure was selected as region of interest in the present study. Indirect immunohistochemistry was applied to visualise the serotonin-1B-receptor-positive neurons. Immunoreactivity was located predominantly within the neuronal cell bodies and adjacent neuronal processes. In the aggressive dogs the BNGs contained a significantly higher number of serotonin-1B-receptor-positive neurons compared to the normally behaving dogs. This number was strongly correlated with the total number of neurons per BNG, which was also significantly increased in aggressive dogs compared to normal dogs. The percentage of neurons expressing the serotonin-1B receptor did not differ significantly between both groups. No significant asymmetries were observed for the number and percentage of serotonin-1B-receptor-positive neurons. Potential relationships between the present findings and the etiology of aggressive behaviour, the neuroprotective role of the serotonin-1B receptor and receptor dysfunction are discussed.
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Affiliation(s)
- C Jacobs
- Department of Morphology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
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Abstract
Cancer metastases (spread to distant organs from the primary tumor site) signify systemic, progressive, and essentially incurable malignant disease. Anorexia and wasting develop continuously throughout the course of incurable cancer. Overall, in Westernized countries nearly exactly half of current cancer diagnoses end in cure and the other half end in death; thus, cancer-associated cachexia has a high prevalence. The pathophysiology of cancer-associated cachexia has two principal components: a failure of food intake and a systemic hypermetabolism/hypercatabolism syndrome. The superimposed metabolic changes result in a rate of depletion of physiological reserves of energy and protein that is greater than would be expected based on the prevailing level of food intake. These features indicate a need for nutritional support, metabolic management, and a clear appreciation of the context of life-limiting illness.
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Affiliation(s)
- Vickie E Baracos
- Department of Oncology, University of Alberta, Cross Cancer Institute, Edmonton, Alberta, Canada, T6G 1Z2.
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Abstract
PURPOSE OF REVIEW In the USA, 8-10 million people are morbidly obese, which is associated with a high frequency of comorbidities. The most effective treatment is surgery. Of around 180,000 bariatric operations performed in 2005, 80% were Roux-en-Y gastric bypass, consisting of a small gastric pouch to minimize food intake and a Roux-en-Y of distal small bowel bypassing the upper gastrointestinal tract. The precise mechanisms whereby Roux-en-Y gastric bypass achieves sustained weight loss remain unknown. To gain insight into the catabolic events of sustained weight loss we developed a diet-induced obese Roux-en-Y gastric bypass rat model. We review our rat model data from the novel viewpoint of the catabolic state, comparing it with the limited human data available and the catabolic events occurring in cancer anorexia/cachexia syndrome. RECENT FINDINGS Current data suggest the involvement of mechanisms other than restrictive and malabsorptive factors of the Roux-en-Y gastric bypass, classically thought of as the mechanisms responsible for weight loss. Based on available data, gastrointestinal hormones and cytokines play a key role in reducing food intake and regulating energy homeostasis. Because of the cross talk between peripheral modulators and the hypothalamus, a critical role for their interaction in the outcome of Roux-en-Y gastric bypass is emerging. SUMMARY In our Roux-en-Y gastric bypass rat model many of the changes in gastrointestinal hormones, adipokines and cytokines as well as in hypothalamic neuropeptides and neurotransmitters resemble the changes observed in the anorexia/cachexia rat model, suggesting that Roux-en-Y gastric bypass triggers a catabolic state responsible for loss of appetite and prolonged body weight reduction.
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Affiliation(s)
- Ana Guijarro
- Surgical Metabolism and Nutrition Laboratory, Department of Surgery, SUNY Upstate Medical University, Syracuse, New York 13021, USA
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Abstract
Anorexia, the loss of the desire to eat, is common in patients with cancer. Studies report a prevalence of up to 66% and clinical practice suggests that it is an almost universal experience as the cancer progresses. It generally leads to a reduction in food intake that contributes to the development of malnutrition and cachexia, impairing quality of life and increasing morbidity and mortality. Successful curative or palliative treatment of the underlying cancer is an effective approach. When this is not possible, there are limited treatment options, which generally have not been shown to be practicable, tolerable, effective or safe in the long-term management of the cachexia-anorexia syndrome. Recent increases in the understanding of the physiology of energy intake and of the pathophysiology of anorexia are helping to guide the development of rational approaches. This journal club provides an outline of the pathophysiology of anorexia and highlights a paper that may provide an exciting glimpse of the future.
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Affiliation(s)
- Andrew Wilcock
- University of Nottingham, Hayward House Macmillan Palliative Care Cancer Unit, Nottingham City Hospital NHS Trust, UK.
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Guijarro A, Laviano A, Meguid MM. Hypothalamic integration of immune function and metabolism. PROGRESS IN BRAIN RESEARCH 2006; 153:367-405. [PMID: 16876587 PMCID: PMC7119041 DOI: 10.1016/s0079-6123(06)53022-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The immune and neuroendocrine systems are closely involved in the regulation of metabolism at peripheral and central hypothalamic levels. In both physiological (meals) and pathological (infections, traumas and tumors) conditions immune cells are activated responding with the release of cytokines and other immune mediators (afferent signals). In the hypothalamus (central integration), cytokines influence metabolism by acting on nucleus involved in feeding and homeostasis regulation leading to the acute phase response (efferent signals) aimed to maintain the body integrity. Peripheral administration of cytokines, inoculation of tumor and induction of infection alter, by means of cytokine action, the normal pattern of food intake affecting meal size and meal number suggesting that cytokines acted differentially on specific hypothalamic neurons. The effect of cytokines-related cancer anorexia is also exerted peripherally. Increase plasma concentrations of insulin and free tryptophan and decrease gastric emptying and d-xylose absorption. In addition, in obesity an increase in interleukin (IL)-1 and IL-6 occurs in mesenteric fat tissue, which together with an increase in corticosterone, is associated with hyperglycemia, dyslipidemias and insulin resistance of obesity-related metabolic syndrome. These changes in circulating nutrients and hormones are sensed by hypothalamic neurons that influence food intake and metabolism. In anorectic tumor-bearing rats, we detected upregulation of IL-1beta and IL-1 receptor mRNA levels in the hypothalamus, a negative correlation between IL-1 concentration in cerebro-spinal fluid and food intake and high levels of hypothalamic serotonin, and these differences disappeared after tumor removal. Moreover, there is an interaction between serotonin and IL-1 in the development of cancer anorexia as well as an increase in hypothalamic dopamine and serotonin production. Immunohistochemical studies have shown a decrease in neuropeptide Y (NPY) and dopamine (DA) and an increase in serotonin concentration in tumor-bearing rats, in first- and second-order hypothalamic nuclei, while tumor resection reverted these changes and normalized food intake, suggesting negative regulation of NPY and DA systems by cytokines during anorexia, probably mediated by serotonin that appears to play a pivotal role in the regulation of food intake in cancer. Among the different forms of therapy, nutritional manipulation of diet in tumor-bearing state has been investigated. Supplementation of tumor bearing rats with omega-3 fatty acid vs. control diet delayed the appearance of tumor, reduced tumor-growth rate and volume, negated onset of anorexia, increased body weight, decreased cytokines production and increased expression of NPY and decreased alpha-melanocyte-stimulating hormone (alpha-MSH) in hypothalamic nuclei. These data suggest that omega-3 fatty acid suppressed pro-inflammatory cytokines production and improved food intake by normalizing hypothalamic food intake-related peptides and point to the possibility of a therapeutic use of these fatty acids. The sum of these data support the concept that immune cell-derived cytokines are closely related with the regulation of metabolism and have both central and peripheral actions, inducing anorexia via hypothalamic anorectic factors, including serotonin and dopamine, and inhibiting NPY leading to a reduction in food intake and body weight, emphasizing the interconnection of the immune and neuroendocrine systems in regulating metabolism during infectious process, cachexia and obesity.
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Affiliation(s)
- Ana Guijarro
- Surgical Metabolism and Nutrition Laboratory, Neuroscience Program, University Hospital, SUNY Upstate Medical University, 750 Adams St., Syracuse, NY 13210, USA
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