Lines of evidence have shown the embryogenic and transgenerational impact of bisphenol A (BPA), an endocrine-disrupting chemical, on immune-metabolic alterations, inflammation, and oxidative stress, while BPA toxic effects in adult obese mice are still overlooked. Here, we evaluate BPA’s worsening effect on several hepatic maladaptive processes associated to high-fat diet (HFD)-induced obesity in mice. After 12 weeks HFD feeding, C57Bl/6J male mice were exposed daily to BPA (50 μg/kg per os) along with HFD for 3 weeks. Glucose tolerance and lipid metabolism were examined in serum and/or liver. Hepatic oxidative damage (reactive oxygen species, malondialdehyde, antioxidant enzymes), and mitochondrial respiratory capacity were evaluated. Moreover, liver damage progression and inflammatory/immune response were determined by histological and molecular analysis. BPA amplified HFD-induced alteration of key factors involved in glucose and lipid metabolism, liver triglycerides accumulation, and worsened mitochondrial dysfunction by increasing oxidative stress and reducing antioxidant defense. The exacerbation by BPA of hepatic immune-metabolic dysfunction induced by HFD was shown by increased toll-like receptor-4 and its downstream pathways (i.e., NF-kB and NLRP3 inflammasome) amplifying inflammatory cytokine transcription and promoting fibrosis progression. This study evidences that BPA exposure represents an additional risk factor for the progression of fatty liver diseases strictly related to the cross-talk between oxidative stress and immune-metabolic impairment due to obesity.

The potential role of brown and beige adipose tissue against obesity has been recognized. Browning, or beiging of white adipose tissue (WAT) is associated with the remodeling of adipocytes and the improvement of their metabolic and secretory functions. Here, palmitoylethanolamide (PEA) restore the plasticity of brown and white adipocytes impaired in mice on a high-fat diet (HFD). Young male C57Bl/6J mice were fed with control (STD) diet or HFD for 12 weeks. Ultramicronized PEA (30 mg/kg/die p.o.) was administered for an additional 7 weeks, together with HFD. PEA recovered interscapular brown fat morphology and function, increasing UCP1 positivity, noradrenergic innervation, and inducing the mRNA transcription of several specialized thermogenic genes. PEA promotes the beige-conversion of the subcutaneous WAT, increasing thermogenic markers and restoring leptin signaling and tissue hormone sensitivity. The pivotal role of lipid-sensing peroxisome proliferator-activated receptor (PPAR)-α in PEA effects was determined in mature 3T3-L1. Moreover, PEA improved mitochondrial bioenergetics in mature adipocytes measured by a Seahorse analyzer and induced metabolic machinery via AMPK phosphorylation. All these outcomes were dampened by the receptor antagonist GW6471. Finally, PEA induced adipogenic differentiation and increased AMPK phosphorylation in human adipose-derived stromal cells (ASCs) obtained from subcutaneous WAT of normal-weight patients and patients with obesity. We identify PEA and PPAR-α activation as the main mechanism by which PEA can rewire energy-storing white into energy-consuming brown-like adipocytes via multiple and converging effects that restore WAT homeostasis and metabolic flexibility.

Among the non-communicable neurological diseases, epilepsy is characterized by abnormal brain activity with several peripheral implications. The role of peripheral inflammation in the relationship between seizure development and nonalcoholic fatty liver disease based on sex difference remains still overlooked. Severe early-life infections lead to increased inflammation that can aggravate epilepsy and hepatic damage progression, both related to increased odds of hospitalization for epileptic patients with liver diseases. Here, we induced a post-natal-day 3 (PND3) infection by LPS (1 mg/kg, i.p.) to determine the hepatic damage in a genetic model of young epileptic WAG/Rij rats (PND45). We evaluated intra- and inter-gender differences in systemic and liver inflammation, hepatic lipid dysmetabolism, and oxidative damage related to mitochondrial functional impairment. First, epileptic rats exposed to LPS, regardless of gender, displayed increased serum hepatic enzymes and altered lipid profile. Endotoxin challenge triggered a more severe inflammatory and immune response in male epileptic rats, compared to females in both serum and liver, increasing pro-inflammatory cytokines and hepatic immune cell recruitment. Conversely, LPS-treated female rats showed significant alterations in systemic and hepatic lipid profiles and reduced mitochondrial fatty acid oxidation. The two different sex-dependent mechanisms of LPS-induced liver injury converge in increased ROS production and related mitochondrial oxidative damage in both sexes. Notably, a compensatory increase in antioxidant defense was evidenced only in female rats. Our study with a translational potential demonstrates, for the first time, that early post-natal infections in epileptic rats induced or worsened hepatic disorders in a sex-dependent manner, amplifying inflammation, lipid dysmetabolism, and mitochondrial impairment.

Epilepsy is a non-communicable neurological disease characterized by abnormal brain activity with conceivable peripheral implications. Few studies examine the role of peripheral and brain inflammation in the relationship between seizure predisposition and nonalcoholic fatty liver disease. Severe early-life infections leading to sepsis results in increased inflammation that can aggravate epilepsy and hepatic damage progression both associated with increased odds for hospital admissions in epileptic patients. Here, we examined the effect of early LPS challenge (1 mg/kg, i.p. at post-natal day3, PND3) in inducing hepatic damage in a genetic model of young epileptic WAG/Rij rats (PND45), evaluating the intra- and inter-gender differences on systemic and liver inflammation, hepatic lipid dysmetabolism and oxidative damage associated to mitochondrial functional impairment. First, epileptic rats exposed to LPS, regardless of gender, displayed increased serum hepatic enzymes and altered lipid profile. Early LPS challenge induced a major inflammatory and immune response in male epileptic rats than females in both serum and liver, increasing pro-inflammatory cytokines and hepatic immune cell recruitment. Conversely, LPS-insulted females showed a marked alteration in hepatic metabolic and lipid profile and the reduction in mitochondrial fatty acid oxidation. The two different gender-related mechanisms of LPS-induced liver injury converge in mitochondrial oxidative damage with intensified ROS production in both sexes, that notably induced a compensatory increase in antioxidant defense only in females. Our study with a translational potential points out that early postnatal infections predispose epileptic rats to develop or worsen hepatic disorders in a sex-dependent manner, amplifying inflammation, lipid dysmetabolism, and mitochondrial impairment.

Bisphenol A (BPA) is an endocrine-disrupting chemical inducing several damages such as neurotoxicity, immunotoxicity, and metabolic disorders. Obesity is the main risk factor for the increased occurrence of metabolic alterations as well as mood disorders. Here, we investigated in obese mice the effects of BPA on anxiety-like behavior, associated with neuroinflammation and immune activation. Male 6 weeks-old C57Bl/6J mice were divided into 4 groups: (I) control group (STD) receiving chow diet and BPA vehicle; (II) STD group treated with BPA (50 μg/kg/die); (III) high-fat diet (HFD) group receiving BPA vehicle; (IV) HFD group treated with BPA. BPA treatment started 12 weeks after HFD feeding and lasted 3 weeks. The open field and elevated plus-maze tests showed in HFD+BPA group the worsening of HFD-induced anxiety-like behavior. The anxiogenic effects of BPA also emerged from hyperactivation of the hypothalamus-pituitary-adrenal gland axis, determined by the increased transcription of Crh and its receptor in the prefrontal cortex (PFC). Furthermore, BPA activated NLRP3 inflammasome and exacerbated the neuroinflammation induced by HFD, increasing IL-1β, TNF-α and monocyte chemoattractant protein (MCP)-1 in PFC. Furthermore, it induced inflammation and monocyte recruitment in hypothalamus and amygdala. Contextually, BPA significantly amplified the immune activation caused by lipid overload as evidenced by the increased expression of TLR-4 and MCP-1 in the PFC and triggered mastocyte activation in the hypothalamus rather than STD mice.

Metabolic alterations, resulting from obesity, drive chronic kidney disease (CKD) through mechanisms including lipotoxicity, inflammation, and fibrosis. Oleoylethanolamide (OEA), an endogenous compound belonging to the N-acylethanolamine family, has been widely studied for its metabolic properties. However, emerging evidence highlights its anti-inflammatory and anti-fibrotic effects. Here, we explored the effect of OEA on high-fat diet (HFD)-induced renal damage associated with obesity in mice. OEA treatment improved kidney function by restoring urine output and reducing proteinuria and albuminuria in obese mice. Moreover, OEA normalized serum creatinine and blood urea nitrogen levels, which were altered by HFD feeding, and decreased the transcription of kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin, associated with renal damage. OEA also counteracted renal glucose dysmetabolism by reducing glycogen content and modulating the protein expression of glucose transporters. Furthermore, OEA exerted marked anti-inflammatory and antifibrotic effects in kidney, further confirmed by a reduction in the transcription of pro-inflammatory and pro-fibrotic markers. OEA reduced renal steatosis, improving lipid metabolism through increased peroxisome proliferator-activated receptor-α and fibroblast growth factor 21 transcription and reduced triglyceride trafficking by the downregulation of diacylglycerol O-acyltransferase 1. Finally, to highlight the direct effect of OEA in the kidney, we confirmed its protective activity against lipotoxicity and demonstrated its ability to improve mitochondrial bioenergetics in human proximal tubular epithelial cells (HK-2). These results indicate that OEA may be a promising therapeutic molecule for restraining CKD-related alterations associated with obesity and metabolic disorders.