Effects of thirty elements on bone metabolism

The presence of metals in the environment is a matter of concern, since human activities are the major cause of pollution and metals can enter the food chain and bioaccumulate in hard and soft tissues/organs, which results in a long half-life of the metal in the body. Metal intoxication has a negative impact on human health and can alter different systems depending on metal type and concentration and duration of metal exposure. The present review focuses on the most common metals found in contaminated areas (cadmium, zinc, copper, nickel, mercury, chromium, lead, aluminum, titanium, and iron, as well as metalloid arsenic) and their effects on bone tissue. Both the lack and excess of these metals in the body can alter bone dynamics. Long term exposure and short exposure to high concentrations induce an imbalance in the bone remodeling process, altering both formation and resorption and leading to the development of different bone pathologies.

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A Review of Metal Exposure and Its Effects on Bone Health.

Lead is an important heavy metal used worldwide in several applications, especially in industry. People exposed to lead can develop a wide range of symptoms associated with lead poisoning. Many effects of lead poisoning are reported in the literature, showing a compromising of whole body health, with symptoms related to cardiovascular, immune, bone, reproductive, hematological, renal, gastrointestinal, and nervous system. However, the molecular lead targets as well as the pathways affected by lead poisoning are not completely described. The aim of this study was to construct a map of metabolic pathways impaired in lead poisoning by evaluating which biomolecules are directly affected by lead. Through manual literature curation, we identified proteins which physically interact with lead and subsequently determined the metabolic pathways those proteins are involved with. At total, we identified 23 proteins involved with heme synthesis, calcium metabolism, neurotransmission, among other biological systems, which helps to understand the wide range of lead-poisoning symptoms.

Lead-interacting proteins and their implication in lead poisoning

Lead removal by a reusable gel cation exchange resin containing nano-scale zero valent iron

Effects of vitamin E on lead-induced impairments in hippocampal synaptic plasticity

The existence of children living at high altitude suffering from lead (Pb) poisoning prompted us to investigate the long term effects of this pollutant on growth and bone biology in growing rats maintained at simulated high altitude (SHA). Pb and hypoxia (HX) significantly reduced body weight (−9.4 % and −24 %; p < 0.01) and length (−3 % and −8 %; p < 0.01); decreased femoral ultimate load (−16 % and −40 %; p < 0.01) and femoral energy absorption capacity (−18 % and −74 %; p < 0.01). Oral pathologic alterations were observed in experimental groups. Our findings revealed growth retardation and damages on femoral and mandibular bones that predispose to fractures.

Effects of lead exposure on growth and bone biology in growing rats exposed to simulated high altitude.

Effects of chronic lead exposure on bone mineral properties in femurs of growing rats.

Chronic lead poisoning magnifies bone detrimental effects in an ovariectomized rat model of postmenopausal osteoporosis.

The objective of the present study was to investigate the effects of chronic lead exposure on the mineral properties of alveolar bone. For this purpose, female Wistar rats (n = 8) were exposed to 1000 ppm lead acetate in drinking water for 90 days, while the control group (n = 5) was treated with sodium acetate. The alveolar bone structure and chemical composition of the dissected mandibles were examined using micro-computed tomography (micro-CT), scanning electron microscopy (SEM), inductively coupled plasma optical emission spectrometry (ICP-OES), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), and X-ray diffraction (XRD) techniques to determine possible alterations in alveolar bone due to lead exposure. In addition, changes in bone mechanical properties were analysed using a three-point bending test. Exposure to lead induced notable changes in bone mineralization and properties, specifically a reduction of the trabecular thickness and bone mineral density. Furthermore, there was a reduction in carbonate content and an increase in bone mineral crystallinity. These changes in bone mineralization could be explained by an alteration in bone turnover due to lead exposure. Three-point bending showed a trend of decreased displacement at failure in the mandibles of lead-exposed rats, which could compromise the mechanical stability and normal development of the dentition.

https://www.mdpi.com/2075-163X/11/6/642/pdf

Ching Ming Lee

Papers

Effects of lead exposure on growth and bone biology in growing rats exposed to simulated high altitude.

Effects of chronic lead exposure on bone mineral properties in femurs of growing rats.

Chronic lead poisoning magnifies bone detrimental effects in an ovariectomized rat model of postmenopausal osteoporosis.

Chronic Lead Exposure Alters Mineral Properties in Alveolar Bone