Drp1 Aggravates Copper Nanoparticle-Induced ER-Phagy by Disturbing Mitochondria-Associated Membranes in Chicken Hepatocytes

Unraveling the Metabolic Pathways Between Metabolic-Associated Fatty Liver Disease (MAFLD) and Sarcopenia

Metabolic-Associated Fatty Liver Disease (MAFLD) is a public health concern that is constantly expanding, with a fast-growing prevalence, and it affects about a quarter of the world's population. This condition is a significant risk factor for cardiovascular, hepatic, and oncologic diseases, such as hypertension, hepatoma, and atherosclerosis. Sarcopenia was long considered to be an aging-related syndrome, but today, it is acknowledged to be secondarily related to chronic diseases such as metabolic syndrome, cardiovascular conditions, and liver diseases, among other comorbidities associated with insulin resistance and chronic inflammation, besides inactivity and poor nutrition. The physiopathology involving MAFLD and sarcopenia has still not been solved. Inflammation, oxidative stress, mitochondrial dysfunction, and insulin resistance seem to be some of the keys to this relationship since this hormone target is mainly the skeletal muscle. This review aimed to comprehensively discuss the main metabolic and physiological pathways involved in these conditions. MAFLD and sarcopenia are interconnected by a complex network of pathophysiological mechanisms, such as insulin resistance, skeletal muscle tissue production capacity, chronic inflammatory state, oxidative stress, and mitochondrial dysfunction, which are the main contributors to this relationship. In addition, in a clinical analysis, patients with sarcopenia and MAFLD manifest more severe hepatitis fibrosis when compared to patients with only MAFLD. These patients, with both disorders, also present clinical improvement in their MAFLD when treated for sarcopenia, reinforcing the association between them. Lifestyle changes accompanied by non-pharmacological interventions, such as dietary therapy and increased physical activity, undoubtedly improve this scenario.

Synergistic effects of lead and copper co-exposure on promoting oxidative stress and apoptosis in the neuronal cells

Exposure to lead (Pb) or copper (Cu) is common and has been associated with increased risk of neurodegenerative disease. However, combined neurotoxic effects of co-exposure to these elements remain unclear. This study aimed to determine the toxic effects of Pb and Cu co-exposure on HT22 cells. In this study, Pb and Cu co-exposure exhibited enhanced toxicity, including increased reactive oxygen species (ROS) and Malondialdehyde (MDA) levels, Superoxide Dismutase 1 (SOD1) activity, lower cell viability and higher apoptotic rates, compared to single-element exposure. Pb and Cu co-exposure also resulted in significantly increased cellular labile Cu level by altering the protein levels of Cu transporters, including Copper Transporter-1 (CTR1), ATPase Copper Transporting-α(ATP7A) and ATPase Copper Transporting-β (ATP7B). Treating with antioxidants or Cu chelator to the co-exposed cells blocked the reduction cell viability and elevation of apoptotic rates. This study suggests that Pb and Cu co-exposure can result in a synergistic toxicity in neuronal cells by inducing oxidative stress and apoptosis. The cellular Cu accumulation may play an important role in inducing these synergistic effects, and both antioxidation and Cu chelation may be promising control measures to alleviate the neurotoxicity of Pb and Cu co-exposure.

Metabolic-Associated Fatty Liver Disease: The Influence of Oxidative Stress, Inflammation, Mitochondrial Dysfunctions, and the Role of Polyphenols

Metabolic-Associated Fatty Liver Disease (MAFLD) is a clinical-pathological scenario that occurs due to the accumulation of triglycerides in hepatocytes which is considered a significant cause of liver conditions and contributes to an increased risk of death worldwide. Even though the possible causes of MAFLD can involve the interaction of genetics, hormones, and nutrition, lifestyle (diet and sedentary lifestyle) is the most influential factor in developing this condition. Polyphenols comprise many natural chemical compounds that can be helpful in managing metabolic diseases. Therefore, the aim of this review was to investigate the impact of oxidative stress, inflammation, mitochondrial dysfunction, and the role of polyphenols in managing MAFLD. Some polyphenols can reverse part of the liver damage related to inflammation, oxidative stress, or mitochondrial dysfunction, and among them are anthocyanin, baicalin, catechin, curcumin, chlorogenic acid, didymin, epigallocatechin-3-gallate, luteolin, mangiferin, puerarin, punicalagin, resveratrol, and silymarin. These compounds have actions in reducing plasma liver enzymes, body mass index, waist circumference, adipose visceral indices, lipids, glycated hemoglobin, insulin resistance, and the HOMA index. They also reduce nuclear factor-KB (NF-KB), interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α), blood pressure, liver fat content, steatosis index, and fibrosis. On the other hand, they can improve HDL-c, adiponectin levels, and fibrogenesis markers. These results show that polyphenols are promising in the prevention and treatment of MAFLD.