Bisphenol A-Induced Endocrine Dysfunction and its Associated Metabolic Disorders.

Bisphenol A (BPA) is an endocrine-disrupting chemical widely present in many consumer goods that poses a significant threat to our health upon exposure. Humans are exposed to BPA, which directly or indirectly causes endocrine dysfunctions that lead to metabolic disorders like obesity, fatty liver diseases, insulin resistance, polycystic ovarian syndrome, and other endocrine- related imbalances. The duration, quantity, and period of exposure to BPA, especially during the critical stage of development, determine its impact on reproductive and non-reproductive health. Because of its endocrine-disrupting effects, the European Chemical Agency has added BPA to the candidate list of chemicals of very serious concern. Due to its estrogenic properties and structural similarities with thyroid hormones, BPA disrupts the endocrine system at different levels. It interacts with estrogen receptors at the molecular level and acts as an antagonist or agonist via an estrogen receptor-dependent signaling pathway. In particular, BPA binds to G-protein coupled receptors and estrogen receptors, activating signaling pathways that influence cellular apoptosis, proliferation, differentiation, and inflammation. BPA acts as an obesogen that promotes adipogenesis and correlates with increased lipid accumulation and elevated expression of adipogenic markers. As a metabolic and endocrine disruptor, BPA impairs cellular homeostasis by increasing oxidative mediators and decreasing antioxidant enzymes, resulting in mitochondrial dysfunction. Due to its endocrine-disrupting properties, BPA exposure induces endocrine dysfunctions, causing metabolic syndrome. This review article gives recent development and novel insights into the cellular and molecular mechanisms of BPA-induced endocrine dysfunctions and their associated metabolic disorders.

Inflammasome Signaling in the Aging Brain and Age-Related Neurodegenerative Diseases.

Inflammasomes are intracellular protein complexes, members of the innate immune system, and their activation and regulation play an essential role in maintaining homeostatic conditions against exogenous and endogenous stimuli. Inflammasomes occur as cytosolic proteins and assemble into a complex during the recognition of pathogen-associated or danger-associated molecular patterns by pattern-recognition receptors in host cells. The formation of the inflammasome complex elicits signaling molecules of proinflammatory cytokines such as interleukin-1ß and interleukin 18 via activation of caspase-1 in the canonical inflammasome pathway whereas caspase-11 in the case of a mouse and caspase-4 and caspase-5 in the case of humans in the non-canonical inflammasome pathway, resulting in pyroptotic or inflammatory cell death which ultimately leads to neuroinflammation and neurodegenerative diseases. Inflammasome activation, particularly in microglial cells and macrophages, has been linked to aging as well as age-related neurodegenerative diseases. The accumulation of abnormal/ misfolded proteins acts as a ligand for inflammasome activation in neurodegenerative diseases. Although recent studies have revealed the inflammasomes' functionality in both in vitro and in vivo models, many inflammasome signaling cascade activations during biological aging, neuroinflammation, and neurodegeneration are still ambiguous. In this review, we comprehensively unveil the cellular and molecular mechanisms of inflammasome activation during neuronal aging and age-related neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, Huntington's disease, multiple sclerosis, prion disease, and amyotrophic lateral sclerosis.