Cadmium inhibits signal transducer and activator of transcription 6 leading to pancreatic β cell apoptosis

Association between Heavy Metals, Metalloids and Metabolic Syndrome: New Insights and Approaches

Metabolic syndrome (MetS) is an important public health issue that affects millions of people around the world and is growing to pandemic-like proportions. This syndrome is defined by the World Health Organization (WHO) as a pathologic condition characterized by abdominal obesity, insulin resistance, hypertension, and hyperlipidemia. Moreover, the etiology of MetS is multifactorial, involving many environmental factors, including toxicant exposures. Several studies have associated MetS with heavy metals exposure, which is the focus of this review. Environmental and/or occupational exposure to heavy metals are a major risk, contributing to the development of chronic diseases. Of particular note, toxic metals such as mercury, lead, and cadmium may contribute to the development of MetS by altering oxidative stress, IL-6 signaling, apoptosis, altered lipoprotein metabolism, fluid shear stress and atherosclerosis, and other mechanisms. In this review, we discuss the known and potential roles of heavy metals in MetS etiology as well as potential targeted pathways that are associated with MetS. Furthermore, we describe how new approaches involving proteomic and transcriptome analysis, as well as bioinformatic tools, may help bring about an understanding of the involvement of heavy metals and metalloids in MetS.

Fluorescent indicators for live-cell and in vitro detection of inorganic cadmium dynamics

Cadmium contamination is a severe threat to the environment and food safety. Thus, there is an urgent need to develop highly sensitive and selective cadmium detection tools. The engineered fluorescent indicator is a powerful tool for the rapid detection of inorganic cadmium in the environment. In this study, the development of yellow fluorescent indicators of cadmium chloride by inserting a fluorescent protein at different positions of the high cadmium-specific repressor and optimizing the flexible linker between the connection points is reported. These indicators provide a fast, sensitive, specific, high dynamic range, and real-time readout of cadmium ion dynamics in solution. The excitation and emission wavelength of this indicator used in this work are 420/485 and 528 nm, respectively. Fluorescent indicators N0C0/N1C1 showed a linear response to cadmium concentration within the range from 10/30 to 50/100 nM and with a detection limit of 10/33 nM under optimal condition. Escherichia coli cells containing the indicator were used to further study the response of cadmium ion concentration in living cells. E. coli N1C1 could respond to different concentrations of cadmium ions. This study provides a rapid and straightforward method for cadmium ion detection in vitro and the potential for biological imaging.