Anika Tschirner

Prevention of liver cancer cachexia-induced cardiac wasting and heart failure

AIMS Symptoms of cancer cachexia (CC) include fatigue, shortness of breath, and impaired exercise capacity, which are also hallmark symptoms of heart failure (HF). Herein, we evaluate the effects of drugs commonly used to treat HF (bisoprolol, imidapril, spironolactone) on development of cardiac wasting, HF, and death in the rat hepatoma CC model (AH-130). METHODS AND RESULTS Tumour-bearing rats showed a progressive loss of body weight and left-ventricular (LV) mass that was associated with a progressive deterioration in cardiac function. Strikingly, bisoprolol and spironolactone significantly reduced wasting of LV mass, attenuated cardiac dysfunction, and improved survival. In contrast, imidapril had no beneficial effect. Several key anabolic and catabolic pathways were dysregulated in the cachectic hearts and, in addition, we found enhanced fibrosis that was corrected by treatment with spironolactone. Finally, we found cardiac wasting and fibrotic remodelling in patients who died as a result of CC. In living cancer patients, with and without cachexia, serum levels of brain natriuretic peptide and aldosterone were elevated. CONCLUSION Systemic effects of tumours lead not only to CC but also to cardiac wasting, associated with LV-dysfunction, fibrotic remodelling, and increased mortality. These adverse effects of the tumour on the heart and on survival can be mitigated by treatment with either the β-blocker bisoprolol or the aldosterone antagonist spironolactone. We suggest that clinical trials employing these agents be considered to attempt to limit this devastating complication of cancer.

Simvastatin reduces wasting and improves cardiac function as well as outcome in experimental cancer cachexia

BACKGROUND Chronic inflammation is common in cancer cachexia (CC) and directly involved in the atrophy seen in this condition. Recently, several groups have described a form of cardiomyopathy in CC animal models. Hence, we investigated the effect of simvastatin with its known anti-inflammatory and cardioprotective effects in a rat model of CC. METHODS Juvenile Wister Han rats (weight approx. 200 g) were inoculated with Yoshida AH-130 hepatoma cells and treated once daily with 0.1, 1, 10 or 20 mg/kg/d simvastatin or placebo for 14 days. Body weight and body composition (NMR) were assessed at baseline and at the end of the study. Cardiac function was analysed by echocardiography at baseline and day 11. RESULTS Tumour-bearing, placebo-treated rats lost 47.9±3.8 g of their initial body weight. Treatment with 0.1, 1, 10 or 20 mg/kg/d simvastatin significantly reduced wasting by 39.6%, 47.6%, 28.5% and 35.4%, respectively (all p<0.05 vs. placebo). This was mainly due to reduced atrophy of lean mass, i.e. muscle mass. Cardiac function was significantly improved, e.g. cardiac output (untreated sham: 78.9 mL/min) was severely impaired in tumour-bearing rats (42.4 mL/min) and improved by 1, 10 or 20 mg/kg/d simvastatin (62.2, 59.0 and 57.0 mL/min, respectively, all p<0.05 vs. placebo). Most importantly, 10 or 20 mg/kg/d simvastatin reduced mortality (HR:0.16, 95%CI:0.04-0.76, p=0.021 and HR:0.16, 95%CI:0.03-0.72, p=0.017 vs placebo, respectively). CONCLUSION Simvastatin attenuated loss of body weight as well as muscle mass and improved cardiac function leading to improved survival in this CC model. Simvastatin may be beneficial in a clinical setting to treat CC.

The xanthine oxidase inhibitor oxypurinol reduces cancer cachexia-induced cardiomyopathy.

BACKGROUND Cachexia is a common complication of cancer and may be responsible for 22% of all cancer-related deaths. The exact cause of death in cancer cachexia patients is unknown. Recently, atrophy of the heart has been described in cancer cachexia animal models, which resulted in impaired cardiac function and is likely to contribute to mortality. In cancer patients hyperuricaemia independent of tumour lysis syndrome is often associated with a worse prognosis. Xanthine oxidase (XO) metabolizes purines to uric acid and its inhibition has been shown to improve clinical outcome in patients with chronic heart failure. METHODS The rat Yoshida AH-130 hepatoma cancer cachexia model was used in this study. Rats were treated with 4 or 40 mg/kg/d oxypurinol or placebo starting one day after tumour-inoculation for maximal 15 days. Cardiac function was analyzed by echocardiography on day 11. RESULTS Here we show that inhibition of XO by oxypurinol significantly reduces wasting of the heart and preserves cardiac function. LVEF was higher in tumour-bearing rats treated with 4 mg/kg/d (61±4%) or 40 mg/kg/d (64±5%) oxypurinol vs placebo (51±3%, both p<0.05). Fractional shortening was improved by 4 mg/kg/d (43±3%) oxypurinol vs placebo (30±2, p<0.05), while 40 mg/kg/d oxypurinol (41±5%) did not reach statistical significance. Cardiac output was increased in the 4 mg/kg/d dose only (71±11 mL/min vs placebo 38±4 mL/min, p<0.01). CONCLUSION Inhibition of XO with oxypurinol has beneficial effects on cardiac mass and function in a rat model of severe cancer cachexia, suggesting that XO might be a viable drug target in cancer cachexia.

Inhibition of xanthine oxidase reduces wasting and improves outcome in a rat model of cancer cachexia

Cachexia is a common co‐morbidity in cancer occurring in up to 80% of patients depending on the type of cancer. Uric acid (UA), the end‐product of the purine metabolism, is elevated in cachexia due to tissue wasting and upregulated xanthine oxidase (XO) activity. High serum UA levels indicate increased XO‐dependent production of oxygen free radicals (reactive oxygen species; ROS) and correlate with metabolic illness and poor survival. We hypothesized that XO‐inhibition might reduce inflammatory signals accounting for tissue wasting and improve survival in experimental cancer cachexia. Animals were inoculated intraperitoneally with AH‐130 hepatoma cells and treated with two XO‐inhibitors: allopurinol [Allo, low (LD) and high dose (HD) 4 and 40 mg/kg/d] and its more effective active metabolite oxypurinol (Oxy, 4 and 40 mg/kg/d) or placebo for 15 days. Weight loss and tissue wasting of both fat and lean tissue (assessed by NMR‐scanning) was reduced by both LD and HD Allo and LD‐Oxy, but not by HD‐Oxy. A robust induction of XO‐activity for generation of reactive oxygen species was seen in the placebo group (assessed by electron paramagnetic spectroscopy), which was reduced by XO‐inhibition. Increased ROS induced cytokine signaling, proteolytic activity and tissue degradation were all attenuated by XO inhibition. Survival was significantly and dose dependently improved. Food intake and spontaneous locomotor activity were higher, indicating a higher quality of life. Inhibition of XO can reduce tissue wasting and improve survival in cancer cachexia and clearly clinical studies are needed.

TWIST1 regulates the activity of ubiquitin proteasome system via the miR-199/214 cluster in human end-stage dilated cardiomyopathy.

BACKGROUND The transcription factor TWIST1 has been described to regulate the microRNA (miR)-199/214 cluster. Genetic disruption of TWIST1 resulted in a cachectic phenotype and early death of the knock-out mice. This might be connected to the activity of the ubiquitin-proteasome-system (UPS), as miR-199a has been suggested to regulate the ubiquitin E2 ligases Ube2i and Ube2g1. METHODS Cardiac tissue from explanted hearts of 42 patients with dilated cardiomyopathy and 20 healthy donor hearts were analysed for protein expression of TWIST1 and its inhibitors Id-1, MuRF-1 and MAFbx, the expression of miR-199a, -199b and -214, as well as the activity of the UPS by using specific fluorogenic substrates. RESULTS TWIST1 was repressed in patients with dilated cardiomyopathy by 43% (p=0.003), while Id1 expression was unchanged. This was paralleled by a reduced expression of miR-199a by 38 ± 9% (p=0.053), miR-199b by 36 ± 13% (p=0.019) and miR-214 by 41 ± 11% (p=0.0158) compared to donor hearts. An increased peptidylglutamyl-peptide-hydrolysing activity (p<0.0001) was observed in the UPS, while the chymotrypsin-like and trypsin-like activities were unchanged. The protein levels of the rate limiting ubiquitin E3-ligases MuRF-1 and MAFbx were up-regulated (p=0.005 and p=0.0156, respectively). Mechanistically silencing of TWIST1 using siRNA in primary rat cardiomyocytes led to a down-regulation of the miR-199/214 cluster and to a subsequent up-regulation of Ube2i. CONCLUSION The TWIST1/miR-199/214 axis is down-regulated in dilated cardiomyopathy, which is likely to play a role in the increased activity of the UPS. This may contribute to the loss of cardiac mass during dilatation of the heart.

Catabolic Signaling and Muscle Wasting After Acute Ischemic Stroke in Mice Indication for a Stroke-Specific Sarcopenia

Background and Purpose— Muscle wasting is a common complication accompanying stroke. Although it is known to impair poststroke recovery, the mechanisms of subacute catabolism after stroke have not been investigated in detail. The aim of this study is to investigate mechanisms of local and systemic catabolism and muscle wasting (sarcopenia) in a model of ischemic stroke systematically. Methods— Changes in body composition and catabolic activation in muscle tissue were studied in a mouse model of acute cerebral ischemia (temporal occlusion of the middle cerebral artery). Tissue wasting (nuclear magnetic resonance spectroscopy), tissue catabolism (caspases-3 and -6, myostatin), and proteasome activity were assessed. Food intake, activity levels, and energy expenditure were assessed, and putative mechanisms of postischemic wasting were tested with appropriate interventions. Results— Severe weight loss in stroke animals (day 3: weight loss, –21.7%) encompassed wasting of muscle (–12%; skeletal and myocardium) and fat tissue (–27%). Catabolic signaling and proteasome activity were higher in stroke animals in the contralateral and in the ipsilateral leg. Cerebral infarct severity correlated with catabolic activity only in the contralateral leg but not in the ipsilateral leg. Lower energy expenditure in stroke animals together with normal food intake and activity levels suggests compensatory mechanisms to regain weight. Interventions (high caloric feeding, &bgr;-receptor blockade, and antibiotic treatment) failed to prevent proteolytic activation and muscle wasting. Conclusions— Catabolic pathways of muscle tissue are activated after stroke. Impaired feeding, sympathetic overactivation, or infection cannot fully explain this catabolic activation. Wasting of the target muscle of the disrupted innervation correlated to severity of brain injury. Our data indicate the presence of a stroke-specific sarcopenia.

Tandospirone reduces wasting and improves cardiac function in experimental cancer cachexia

BACKGROUND Cancer cachexia is thought to be the cause of >20% of cancer related deaths. Symptoms of cancer cachexia patients include depression and anorexia significantly worsening their quality of life. Moreover, in rodent models of cancer cachexia atrophy of the heart has been shown to impair cardiac function. Here, we characterize the effects of the antidepressant and anxiolytic drug tandospirone on wasting, cardiac function and survival in experimental cancer cachexia. METHODS The well-established Yoshida hepatoma rat model was used and tumor-bearing rats were treated with 1mg/kg/d (LD), 10mg/kg/d (HD) tandospirone or placebo. Weight, body composition (NMR), cardiac function (echocardiography), activity and food intake were assessed. Noradrenalin and cortisol were measured in plasma and caspase activity in skeletal muscle. RESULTS Ten mg/kg/d tandospirone decreased the loss of body weight (p=0.0003) compared to placebo animals, mainly due to preservation of muscle mass (p<0.001), while 1mg/kg/d tandospirone was not effective. Locomotor activity (p=0.0007) and food intake (p=0.0001) were increased by HD tandospirone. The weight (p=0.0277) and function of heart (left ventricular mass, fractional shortening, stroke volume, ejection fraction, all p<0.05) were significantly improved. In the HD tandospirone group, plasma levels of noradrenalin and cortisol were significantly reduced by 49% and 52%, respectively, which may have contributed to the lower caspase activity in the gastrocnemius muscle. Most importantly, HD tandospirone significantly improved survival compared to placebo rats (HR: 0.34; 95% CI: 0.13-0.86; p=0.0495). CONCLUSION Tandospirone showed significant beneficial effects in the Yoshida hepatoma cancer cachexia model and should be further examined as a prospective drug for this syndrome.

Influence of cancer cachexia on drug liver metabolism and renal elimination in rats

Body wasting and cachexia change body composition and organ function, with effects on drug pharmacokinetics. The aim of this study was to investigate how cancer and cancer cachexia modify liver metabolism and renal drug elimination in rats.

Megestrol acetate improves cardiac function in a model of cancer cachexia-induced cardiomyopathy by autophagic modulation

Cachexia is a complex metabolic syndrome associated with cancer. One of the features of cachexia is the loss of muscle mass, characterized by an imbalance between protein synthesis and protein degradation. Muscle atrophy is caused by the hyperactivation of some of the main cellular catabolic pathways, including autophagy. Cachexia also affects the cardiac muscle. As a consequence of the atrophy of the heart, cardiac function is impaired and mortality is increased. Anti‐cachectic therapy in patients with cancer cachexia is so far limited to nutritional support and anabolic steroids. The use of the appetite stimulant megestrol acetate (MA) has been discussed as a treatment for cachexia.

Febuxostat improves outcome in a rat model of cancer cachexia

Activity of xanthine oxidase is induced in cancer cachexia, and its inhibition by allopurinol or oxypurinol improves survival and reduces wasting in the Yoshida hepatoma cancer cachexia model. Here, we tested the effects of the second‐generation xanthine oxidase inhibitor febuxostat compared with placebo in the same model as used previously by our group.