Determination of copper poisoning in Wilson’s disease using laser ablation inductively coupled plasma mass spectrometry

Abstract

Copper (Cu) is an essential trace element that is vital to the health of all living organisms. As a transition metal, it is involved in a myriad of biological processes. Balance studies estimated that the adult human requirement for copper is in the range of 1.3 to 2 mg per day. Cu deficiency alters immune function, neuropeptide synthesis and antioxidant defense, while the excess in Cu results in oxidative stress and progressive structural damage of mitochondrial and clinically in hepatic and/or neurological symptoms. This becomes particularly visible in Wilson's disease (WD) representing a rare autosomal recessive inherited disorder with a disease prevalence of about 1 in 30,000 people. The affected gene, i.e., ATP7B, belongs to the class of ATP-dependent, P-type Cu-transporting ATPases. To understand the pathomechanism in WD, several experimental models for studying WD were established. Independent studies performed in these models showed that the inactivation of the Atp7b gene results in a gradual increase in Cu in many organs during life span. However, the exact distribution of Cu and the potential impact of elevated Cu concentrations on other metals within the tissue are only sparely analyzed. Recently, novel laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS)-based protocols for metal bio-imaging in liver and brain were established. In the present review, we will discuss the methodological background of this innovative technique and summarize our experiences using LA-ICP-MS imaging in biological monitoring, exact measurement, and spatial assignment of metals within tissue obtained from Atp7b null mice and clinical specimens taken from patients suffering from genetically confirmed WD. Using WD as an example, the data discussed demonstrates that LA-ICP-MS has multi-element capability, allowing precise measurement and visualization of metals in the tissue with high spatial resolution, sensitivity, quantification ability, and exceptional reproducibility.

Accurate Measurement of Copper Overload in an Experimental Model of Wilson Disease by Laser Ablation Inductively Coupled Plasma Mass Spectrometry

“…Recently, we established novel LA-ICP-MS-based protocols for metal bio-imaging in different organs including liver, kidney, and brain [ 19 , 20 ]. We have already comprehensively demonstrated that respective protocols are highly suitable to identify and quantify copper deposits in experimental and clinical samples of WD [ 6 , 7 , 21 , 22 , 23 ]. This technique provides quantitative information about major, minor, and trace elements with wide element coverage and excellent limits of detection [ 24 ].…”

Relevance of Autophagy in Parenchymal and Non-Parenchymal Liver Cells for Health and Disease

“…Another inherited disorder reflecting the importance of autophagy in liver homeostasis is Wilson’s disease, also known as hepatolenticular degeneration or “copper storage disease”. It represents a rare autosomal recessive disorder caused by mutation in the ATPase copper transporting protein ATP7B, preventing the body from removing excess copper and leading to accumulation of this trace metal in liver and brain [27]. Recently, it was shown that ATP7B-deficient cells showed significant increased expression of autophagy-associated genes when compared to control cells.…”

Software solutions for evaluation and visualization of laser ablation inductively coupled plasma mass spectrometry imaging (LA-ICP-MSI) data: a short overview

“…3) enables easy adaptation to special requirements and simple transfer to other systems. Its simplicity further facilitates the quick generation of high-resolution images that can be exported to several common image formats (JPEG, TIFF), which can be depicted in different pseudo-color scales [24–32]. ELAI has an overall simple workflow in data analysis and contains special functions and features for calibration, de-spiking, and image export.…”