Diet-induced obesity does not exacerbate cachexia in male mice bearing Lewis-lung carcinoma tumors

Cachexia is a muscle-wasting syndrome commonly observed in patients with cancer, which can significantly worsen clinical outcomes. Because of a global rise in obesity, the coexistence of cachexia in obese individuals poses unique challenges, with the impact of excessive adiposity on cachexia severity and underlying pathophysiology not well defined. Understanding the interplay between cachexia and obesity is crucial for improving diagnosis and treatment strategies for these patients; therefore, the present study examined differences in cachexia between lean and obese mice bearing Lewis lung carcinoma (LLC) tumors. Nine-week-old, male C57Bl6J mice were placed on either a chow or a high-fat diet (HFD) for 9 wk. After the diet intervention, mice were inoculated with LLC or vehicle. Markers of cachexia, such as body and muscle loss, were noted in both chow and HFD groups with tumors. Tumor weight of HFD animals was greater than that of chow. LLC tumors reduced gastrocnemius, plantaris, and soleus mass, regardless of diet. The tibialis anterior and plantaris mass and cross-sectional area of type IIb/x fibers in the gastrocnemius were not different between HFD-chow, HFD-tumor, and chow-tumor. Using RNA sequencing (RNA-seq) of the plantaris muscle from chow-tumor and HFD-tumor groups, we identified ∼400 differentially expressed genes. Bioinformatic analysis identified changes in lipid metabolism, mitochondria, bioenergetics, and proteasome degradation. Atrophy was not greater despite larger tumor burden in animals fed an HFD, and RNA-seq data suggests that partial protection is mediated through differences in mitochondrial function and protein degradation, which may serve as future mechanistic targets.NEW & NOTEWORTHY This study provides timely information on the interaction between obesity and cancer cachexia. Lean and obese animals show signs of cachexia with reduced body weight, adipose tissue, and gastrocnemius muscle mass. There was not significant wasting in the tibialis anterior, plantaris, or fast twitch fibers in the gastrocnemius muscle of obese animals with tumors. RNA-seq analysis reveals that obese tumor bearing animals had differential expression of mitochondria- and degradation-related genes, which may direct future studies in mechanistic research.

Potential Protein Blood-Based Biomarkers in Different Types of Dementia: A Therapeutic Overview

Abstract:

Biomarkers capable of identifying and distinguishing types of dementia such as Alzheimer's disease (AD), Parkinson's disease dementia (PDD), Lewy body dementia (LBD), and frontotemporal dementia (FTD) have been become increasingly relentless. Studies of possible biomarker proteins in the blood that can help formulate new diagnostic proposals and therapeutic visions of different types of dementia are needed. However, due to several limitations of these biomarkers, especially in discerning dementia, their clinical applications are still undetermined. Thus, the updating of biomarker blood proteins that can help in the diagnosis and discrimination of these main dementia conditions is essential to enable new pharmacological and clinical management strategies, with specificities for each type of dementia. To review the literature concerning protein blood-based AD and non-AD biomarkers as new pharmacological targets and/or therapeutic strategies. Recent findings for protein-based AD, PDD, LBD, and FTD biomarkers are focused on in this review. Protein biomarkers were classified according to the pathophysiology of the dementia types. The diagnosis and distinction of dementia through protein biomarkers is still a challenge. The lack of exclusive biomarkers for each type of dementia highlights the need for further studies in this field. Only after this, blood biomarkers may have a valid use in clinical practice as they are promising to help in diagnosis and in the differentiation of diseases.

Apolipoprotein E ε4 allele impairs cortical activity in healthy aging and Alzheimer's disease

AIM

To investigate the influence of apolipoprotein E (APOE) genotype on cortical activity, using the event-related potential P300 in healthy older adults and individuals with Alzheimer's disease (AD).

METHODS

A cohort of 37 healthy older adults and 48 with AD participated in this study and completed an auditory oddball task using electroencephalographic equipment with 21 channels (10-20 system). APOE genotyping was obtained by real-time PCR.

RESULTS

AD presented increased P300 latency and lower P300 amplitude, compared to healthy older adults. AD APOE ε4 carriers presented increased P300 latency in F3 (420.7 ± 65.8 ms), F4 (412.0 ± 49.0 ms), C4 (413.0 ± 41.1 ms) and P3 (420.4 ± 55.7 ms) compared to non-carriers (F3 = 382.5 ± 56.8 ms, p < 0.01; F4 = 372.2 ± 56.7 ms, p < 0.01; C4 = 374.2 ± 51.7 ms, p < 0.01; P3 = 384.4 ± 44.4 ms, p < 0.01). Healthy older adults APOE ε4 carriers presented lower Fz amplitude (2.6 ± 1.5 μV) compared to non-carriers (4.9 ± 2.9 μV; p = 0.02). Linear regression analysis showed that being a carrier of APOE ε4 allele remained significantly associated with P300 latency even after adjusting for sex, age, and cognitive grouping. APOE ε4 allele increases P300 latency (95% CI 0.11-0.98; p = 0.02).

CONCLUSION

APOE ε4 allele negatively impacts cortical activity in both healthy older adults and AD individuals.

A Systematic Review of Altered P300 Event-Related Potential in Apolipoprotein E4 (APOE4) Carriers

BACKGROUND

Apolipoprotein ε4 allele (APOE4) is the strongest genetic risk factor for Alzheimer's disease and seems to be related to cognitive decline and damaged event-related potential P300, which is a sensitive measure to assess cognitive processing.

OBJECTIVE

This research aims to critically review the existing scientific evidence regarding the association between APOE4 and P300.

METHODS

A systematic review was carried out up to January 2020 on the following databases: Web of Science, Scopus and Medline/PubMed. Articles were considered for inclusion if they are original research that provided information regarding the association between APOE4 and P300, available in English, Spanish, or Portuguese, and available in full text. The methodological quality of the studies selected was evaluated using the quality assessment tool for observational cohort and cross-sectional studies recommended by Cochrane.

RESULTS

Out of 993 studies, 14 met the inclusion criteria. The results obtained showed that APOE4 is related to a longer P300 latency. However, the data supplied do not allow us to confirm if this relationship also occurs in amplitude measures. Moreover, it was observed that APOE genotype may influence P300 in different ages, from younger individuals to demented older people.

CONCLUSION

Evidence shows that APOE4 negatively influences cortical activities related to cognitive functions, as indicated by P300.

Identifying Frailty Levels and Associated Factors in a Population Living in the Context of Poverty and Social Vulnerability

This study aimed to investigate a vulnerable population living in the context of poverty in a Brazilian municipality, in order to identify the factors that are associated with frailty syndrome in elderly people. From the total population living in the area, a random sample of 363 community-dwelling people, 60 years and older, age and gender-stratified, was selected to participate in the research. After losses, a sample of 304 older adults was classified as non-frail, pre-frail and frail. According to the Fried frailty criteria, the prevalence was 12.2% for non-frail individuals, 60.5% pre-frail and 27.3% frail. The main factors associated with frailty in the studied sample were low level of physical activity (OR: 5.2, 95%CI: 2.5-11.0), the occurrence of two or more falls within 12 months (OR: 3.1, 95%CI: 1.4-7.1), mobility deficits (OR: 3.0, 95%CI: 1.5-5.8), and depressive symptoms (OR: 1.9, 95%CI: 1.1-3.7). This study identified the most important factors that must be evaluated to identify frailty syndrome in a socially vulnerable population in the context of poverty. The data should help to encourage effective strategies concerning public health policies for this population.

Effects of Square-Stepping Exercise on balance and depressive symptoms in older adults

The aim of this study was analyze the effects of Square-Stepping Exercise (SSE) on depressive symptoms, balance and functional mobility in older adults. Participants were distributed into two groups: Trained Group (TG), who performed a 16-week intervention with SSE and Control Group (CG), who performed only evaluations. The Berg Balance Scale and Time Up and Go Test (TUG) constituted the evaluation protocol to verify balance and functional mobility. Geriatric Depression Scale-short form (GDS-15) was applied for measure depressive symptoms. Evaluations were realized pre and post 16-week. Significant improvements were observed in the TG with the maintenance of GDS-15 scores and on the time to perform the TUG test which reflects better functional mobility than the CG. This could lead to conclude that the SSE is an important tool for improve balance, prevent falls and decrease depression symptoms.

Serum homocysteine and physical exercise in patients with Parkinson's disease

BACKGROUND

Hyperhomocysteinemia is a major risk factor for cerebral and peripheral vascular diseases, as well as cortical and hippocampal injury, including an increased risk of dementia and cognitive impairment. Elevated serum homocysteine (Hcy) concentrations are common in patients with Parkinson's disease (PD) who have been treated with levodopa; however, physical exercises can help reduce Hcy concentrations. The aim of the present study was to compare serum Hcy levels in patients with PD who partook in regular physical exercises, sedentary PD patients, and healthy controls.

METHODS

Sixty individuals were enrolled in the present study across three groups: (i) 17 patients who did not partake of any type of exercise; (ii) 24 PD patients who exercised regularly; and (iii) 19 healthy individuals who did not exercise regularly. All participants were evaluated by Hoehn and Yahr scale, the Unified Parkinson's Disease Rating Scale (UPDRS) and Schwab and England scale (measure daily functionality). The serum levels of Hcy were analyzed by blood samples collected of each participant. An analysis of variance and a Tukey's post hoc test were applied to compare and to verify differences between groups. Pearson's correlation and stepwise multiple regression analyses were used to consider the association between several variables.

RESULTS

Mean plasma Hcy concentrations in individuals who exercised regularly were similar to those in the healthy controls and significantly lower than those in the group that did not exercise at all (P= 0.000). In addition, patients who did not exercise were receiving significantly higher doses of levodopa than those patients who exercised regularly (P= 0.001). A positive relationship between levodopa dose and Hcy concentrations (R(2) = 0.27; P= 0.03) was observed in patients who did not exercise, but not in those patients who exercised regularly (R(2) = 0.023; P= 0.15).

CONCLUSIONS

The results of the present study suggest that, even with regular levodopa therapy, Hcy concentrations in PD patients who exercise regularly are significantly lower than in patients who do not exercise and are similar Hcy concentrations in healthy controls.

Apathy in Alzheimer's disease: Contribution to a clinical view on progression of dementia

In addition to cognitive impairment, apathy is increasingly recognized as an important neuropsychiatric syndrome in Alzheimer’s disease (AD).

Capacidade aeróbia de ratos alimentados com dieta rica em frutose

INTRODUÇÃO: Evidências apontam que a ingestão exacerbada de frutose pode desencadear distúrbios característicos da síndrome metabólica. OBJETIVOS: Analisar os efeitos da ingestão de dieta rica em frutose sobre aspectos metabólicos de ratos da linhagem Wistar. Adicionalmente, verificar a capacidade aeróbia através da identificação da máxima fase estável de lactato (MFEL). MÉTODOS: Dezesseis ratos foram separados em dois grupos de oito animais: a) controle, alimentados com dieta balanceada, e b) frutose, alimentados com dieta rica em frutose. Foram analisadas a tolerância à glicose (área sob a curva de glicose durante teste de tolerância à glicose), sensibilidade à insulina (taxa de remoção da glicose sérica após sobrecarga exógena de insulina), perfil lipídico sérico e concentração de lactato sanguíneo [lac]s durante exercício na intensidade da MFEL. RESULTADOS: Teste t não pareado (p < 0,05) revelou diferença para a tolerância à glicose e triglicérides, porém não houve diferença na sensibilidade à insulina e na [lac]s. Anova one way com post hoc de Newman-Keuls (p < 0,05) revelou diferença para a cinética da glicose durante o teste de tolerância, mas não para a cinética do lactato durante exercício na MSSL. CONCLUSÃO: As Alterações fisiológicas provocadas pela dieta rica em frutose e inerentes à síndrome metabólica não prejudicam a capacidade aeróbia de ratos.