Hepatotoxicity and proteomic mechanism of Di-n-butyl-di-(4-chlorobenzohydroxamato)tin(IV) (DBDCT) in vivo

Galectin-1-Dependent Mitochondria Apoptosis Plays an Essential Role in the Potential Protein Targets of DBDCT-Induced Hepatotoxicity as Revealed by Quantitative Proteomic Analyses

Di-n-butyl-di-(4-chlorobenzohydroxamato) tin(IV) (DBDCT), a new patent agent, exhibited strong antitumor activity. In some cases, its activity was close to or even higher than cisplatin, a first-line clinical metallic agent. Similar to platinum compounds, it also showed toxicity. However, the effective targets and mechanisms for specific toxicity and biological activity are still unclear. In this study, proteomic analysis revealed that 146 proteins (98 upregulated and 48 downregulated) were differentially identified by label-free LC-MS/MS after DBDCT treatment. Meanwhile, network analysis of these differential proteins suggested that protein Galectin-1 (Gal-1) could regulate the apoptosis process (15 related proteins), which played an essential role in the potential targets of DBDCT-induced hepatotoxicity. Furthermore, it was demonstrated that DBDCT might promote ROS production, activate NF-κB p65, inhibit Ras and p-ERK1/2 expressions, increase the level of Gal-1, subsequently upregulate the expressions of Bax, p53, Fas, and FasL, and downregulate the expression of Bcl-2. As a result of these modulations, caspase cascades were finally activated, which executed apoptosis in HL7702 liver cells. Correspondingly, NAC (inhibitor of ROS), PDTC (inhibitor of NF-κB), EGF (ERK1/2 activator), and OTX008 (inhibitor of Gal-1) were found to reverse and abolish the DBDCT-associated cytotoxicity partially. In conclusion, Gal-1 might be the potential target for toxicity and biological activity. Moreover, the present study will lay the groundwork for future research about di-n-butyl-di-(4-chlorobenzohydroxamato) tin structure optimization and developing it into a new potential anticancer agent.

Organotin Compounds Toxicity: Focus on Kidney

Organotin compounds (OTs) are synthetic persistent organometallic xenobiotics widely used in several commercial applications. They exert well-described harmful effects in brain, liver, adipose tissue, and reproductive organs, as they are endocrine-disrupting chemicals (EDCs), but the effects in the kidneys are less known. The kidneys are especially vulnerable to environmental contaminants because they are a metabolizing site of xenobiotics, therefore, pollutants can accumulate in renal tissue, leading to impaired renal function and to several renal abnormalities. Individuals chronically exposed to OTs present a threefold increase in the prevalence of kidney stones. These compounds can directly inhibit H⁺/K⁺-ATPase in renal intercalated cells, resulting in hypokalemia, renal tubular acidity, and increased urinary pH, which is a known risk factor for kidney stones formation. OTs effects are not only limited to induce nephrolithiasis, its nephrotoxicity is also due to increased reactive oxygen species (ROS). This increase leads to lipid peroxidation, abnormal cellular function, and cell death. Combined, the enzymatic and non-enzymatic antioxidant defense systems become deficient and there is a consequent uncontrolled generation of ROS that culminates in renal tissue damage. Still, few epidemiological and experimental studies have reported renal impact correlated to OTs exposure. This lack of investigation of the complete effect of OTs in renal function and structure led us to perform this review reporting the main researches about this subject.