Cachexia, a paraneoplastic syndrome markedly associated with worsened prognosis in cancer patients, provokes profound wasting of both lean and adipose mass in an association with a state of metabolic "chaos". The white adipose tissue responds to cachexia with marked local inflammation and may be thus a relevant contributor to systemic inflammation. To address this hypothesis we examined the correlation between tissue expression of adipokines and plasma concentration in cachectic and stable weight patients with or without cancer. Adiponectin and liver-derived CRP concentration were significantly higher in the cachectic groups when compared with stable weight patients (P<0.01). The concentration of plasma IL-6 was higher (11.4-fold) in the cancer cachectic group when compared with weight-stable controls, and presented a significant correlation with the presence of cancer (P<0.001). A marked increase (5-fold) in IL-6 as a result of the interaction between the presence of cachexia and the presence of tumour was observed in the subcutaneous tissue of the patients, yet not in the visceral depot. Plasma adiponectin levels were higher in cachectic cancer patients, compared with stable weight cancer patients individually matched by age, sex, and BMI, and the subcutaneous depot was found to be the main contributing tissue, rather than the visceral pad. Based on the results we concluded that the subcutaneous adipose tissue is associated with plasma changes that may function as markers of cachexia.

Background and aimsCachexia is a syndrome characterized by marked involuntary loss of body weight. Recently, adipose tissue (AT) wasting has been shown to occur before the appearance of other classical cachexia markers. We investigated the composition and rearrangement of the extracellular matrix, adipocyte morphology and inflammation in the subcutaneous AT (scAT) pad of gastrointestinal cancer patients.MethodsSurgical biopsies for scAT were obtained from gastrointestinal cancer patients, who were signed up into the following groups: cancer cachexia (CC, n = 11), weight‐stable cancer (WSC, n = 9) and weight‐stable control (non‐cancer) (control, n = 7). The stable weight groups were considered as those with no important weight change during the last year and body mass index <25 kg/m2. Subcutaneous AT fibrosis was quantified and characterized by quantitative PCR, histological analysis and immunohistochemistry.ResultsThe degree of fibrosis and the distribution and collagen types (I and III) were different in WSC and CC patients. CC patients showed more pronounced fibrosis in comparison with WSC. Infiltrating macrophages surrounding adipocytes and CD3 Ly were found in the fibrotic areas of scAT. Subcutaneous AT fibrotic areas demonstrated increased monocyte chemotactic protein 1 (MCP‐1) and Cluster of Differentiation (CD)68 gene expression in cancer patients.ConclusionsOur data indicate architectural modification consisting of fibrosis and inflammatory cell infiltration in scAT as induced by cachexia in gastrointestinal cancer patients. The latter was characterized by the presence of macrophages and lymphocytes, more evident in the fibrotic areas. In addition, increased MCP‐1 and CD68 gene expression in scAT from cancer patients may indicate an important role of these markers in the early phases of cancer.

Cancer cachexia induces loss of fat mass that accounts for a large part of the dramatic weight loss observed both in humans and in animal models; however, the literature does not provide consistent information regarding the set point of weight loss and how the different visceral adipose tissue depots contribute to this symptom. To evaluate that, 8-week-old male Wistar rats were subcutaneously inoculated with 1 ml (2!10 7 ) of tumour cells (Walker 256). Samples of different visceral white adipose tissue (WAT) depots were collected at days 0, 4, 7 and 14 and stored at K80 8C (seven to ten animals/each day per group). Mesenteric and retroperitoneal depot mass was decreased to the greatest extent on day 14 compared with day 0. Gene and protein expression of PPARg2 (PPARG) fell significantly following tumour implantation in all three adipose tissue depots while C/EBPa (CEBPA) and SREBP-1c (SREBF1) expression decreased over time only in epididymal and retroperitoneal depots. Decreased adipogenic gene expression and morphological disruption of visceral WAT are further supported by the dramatic reduction in mRNA and protein levels of perilipin. Classical markers of inflammation and macrophage infiltration (f4/80, CD68 and MIF-1a) in WAT were significantly increased in the later stage of cachexia (although showing a incremental pattern along the course of cachexia) and presented a depot-specific regulation. These results indicate that impairment in the lipid-storing function of adipose tissue occurs at different times and that the mesenteric adipose tissue is more resistant to the 'fat-reducing effect' than the other visceral depots during cancer cachexia progression.

Cachexia affects about 80% of gastrointestinal cancer patients. This multifactorial syndrome resulting in involuntary and continuous weight loss is accompanied by systemic inflammation and immune cell infiltration in various tissues. Understanding the interactions among tumor, immune cells, and peripheral tissues could help attenuating systemic inflammation. Therefore, we investigated inflammation in the subcutaneous adipose tissue and in the tumor, in weight stable and cachectic cancer patients with same diagnosis, in order to establish correlations between tumor microenvironment and secretory pattern with adipose tissue and systemic inflammation. Infiltrating monocyte phenotypes of subcutaneous and tumor vascular-stromal fraction were identified by flow cytometry. Gene and protein expression of inflammatory and chemotactic factors was measured with qRT-PCR and Multiplex Magpix® system, respectively. Subcutaneous vascular-stromal fraction exhibited no differences in regard to macrophage subtypes, while in the tumor, the percentage of M2 macrophages was decreased in the cachectic patients, in comparison to weight-stable counterparts. CCL3, CCL4, and IL-1β expression was higher in the adipose tissue and tumor tissue in the cachectic group. In both tissues, chemotactic factors were positively correlated with IL-1β. Furthermore, positive correlations were found for the content of chemoattractants and cytokines in the tumor and adipose tissue. The results strongly suggest that the crosstalk between the tumor and peripheral tissues is more pronounced in cachectic patients, compared to weight-stable patients with the same tumor diagnosis.

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. melanocortin; cytokines; serotonin; malonyl-coenzyme A; vagus nerve; sympathetic output THE ANOREXIA-CACHEXIA SYNDROME is a debilitating condition characterizing the clinical journey of patients suffering from chronic diseases including cancer, chronic obstructive pulmonary disease, tuberculosis, chronic heart failure, and end-stage renal insufficiency (64). As an experimental model, it represents a reliable and unique tool for the investigation of the mechanisms regulating energy intake and homeostasis. Beyond its relevance to human physiology, this syndrome impacts on clinical practice since it is highly prevalent and negatively influences patients' morbidity, mortality (66), and quality of life (57).The anorexia-cachexia syndrome is clinically characterized by a number of signs and symptoms interfering with energy intake (i.e., reduced appetite, early satiety, changes in taste/ smell) and affecting nutritional status (i.e., increased metabolic rate, weight loss, hormonal alterations, muscle and adipose tissue wasting, functional impairment, fatigue). At the biochemical and molecular levels, the main features of the anorexia-cachexia syndrome are the profound alterations of brain neurochemis...

Amino acids such as leucine and its metabolite α-ketoisocaproate (KIC), are returning to be the focus of studies, mainly because of their anti-catabolic properties, through inhibition of muscle proteolysis and enhancement of protein synthesis. It is clear that these effects may counteract catabolic conditions, as well as enhance skeletal muscle mass and strength in athletes. Moreover, beta-hydroxy-beta-methylbutyrate (HMB) has been shown to produce an important effect in reducing muscle damage induced by mechanical stimuli of skeletal muscle. This review aims to describe the general scientific evidence of KIC and HMB supplementation clinical relevance, as well as their effects (e.g., increases in skeletal muscle mass and/or strength), associated with resistance training or other sports. Moreover, the possible mechanisms of cell signaling regulation leading to increases and/or sparing (during catabolic conditions) of skeletal muscle mass are discussed in detail based on the recent literature.

The adipose tissue (AT) is severely affected by cachexia, a paraneoplastic syndrome, which increases the morbidity and mortality of cancer. There is, however, a heterogeneous response to the condition, according to the AT depot. As plasma leptin concentration has been often reported to vary in cachexia, we have measured (species specific radioimmunoassay) the local concentration of leptin in three AT depots: retroperitoneal (RPAT), epididymal (EAT) and mesenteric (MES) of Walker 256 tumour-bearing rats. A reduced concentration of leptin ( P<0.0001) was found in all the depots and in the plasma of the cachectic rats, compared with controls already from day 4 after tumour cell injection. The presence of a cell infiltrate was observed in all AT obtained from the tumour-bearing animals. Ultrastructural analysis, along with immunocytochemistry for RT1B (indicating the presence of MHCII) and using antibody against mononuclear phagocytes, showed the cells to be macrophages. The profile of TNFalpha and PGE2 secretion by the infiltrate was investigated (commercial kits). There was increased production of both factors by the cells of all AT ( P<0.05) compared with peritoneal macrophages obtained from the cachectic rats, while the cells isolated from MES showed the highest synthesis of TNFalpha. The results suggest a possible modulation of the chronic locally produced TNFalpha and PGE2 upon leptin synthesis by the AT of the cachectic rats.

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