Comparative proteomic analysis reveals heart toxicity induced by chronic arsenic exposure in rats

Combined bisoprolol and trimetazidine ameliorate arsenic trioxide -induced acute myocardial injury in rats: targeting PI3K/GSK-3β/Nrf2/HO-1 and NF-κB/iNOS signaling pathways, inflammatory mediators and apoptosis

BACKGROUND

Arsenic-trioxide (ATO) is an effective therapy for acute promyelocytic leukemia. Unfortunately, its utility is hindered by the risk of myocardial injury. Both bisoprolol (BIS) and trimetazidine (TMZ) have various pharmacological features, including anti-oxidant, anti-inflammatory, and anti-apoptotic properties.

AIM

The cardioprotective effects of BIS and TMZ were studied, and their mechanistic role in ameliorating ATO-induced myocardial injury.

MATERIALS AND METHODS

Forty male Wistar rats were randomly allotted into five groups as follows: normal control group (received normal saline, orally), ATO group (7.5 mg/kg, orally), BIS (8 mg/kg, orally), TMZ (60 mg/kg, orally), and finally combination group (BIS+TMZ+ATO). Following 21 days, samples of serum and cardiac tissues were obtained to perform biochemical, molecular, and histopathological investigations.

RESULTS

The present study showed that ATO caused myocardial injury evidenced by changes in serum biomarkers (Aspatate aminotransferase, alanine aminotransferase, alkaline phosphatase, lactate dehydrogenase, creatine kinase-MB, and cardiac troponin-1), electrolyte imbalance, and lipid profiles alongside histopathologic changes. In addition, ATO administration significantly elevated malondialdehyde, nicotinamide adenine dinucleotide phosphate hydrogen oxidase, myloperoxidase, total nitrite, inducible nitric oxide synthase, tumor necrosis factor-alpha, interleukin-1β, interleukin-6, 8-Hydroxy-2'-deoxyguanosine, nuclear factor NF-kappa-B p65 subunit, glycogen synthase kinase-3 beta, and caspase-3 expression contemporaneously with down-regulation of reduced glutathione, glutathione peroxidase, superoxide dismutase, catalase, heme oxygenase 1, nuclear factor erythroid 2-related factor 2, phosphatidylinositol-3 kinase, p-PI3K, and Bcl-2 expression. Interestingly, pretreatment with BIS and TMZ significantly reversed the detrimental effects of ATO-induced myocardial injury at both cellular and molecular levels. Otherwise, combining the two drugs displayed more enhancement than each drug alone.

CONCLUSION

The present research depicted that BIS and TMZ have the potential to protect the heart and provide therapeutic benefits by preventing acute heart injury induced by ATO. This is achieved by reversing the redox-sensitive pathway, reducing inflammation, and inhibiting apoptosis.

Proteomics reveals that nanoplastics with different sizes induce hepatocyte apoptosis in mice through distinct mechanisms involving mitophagy dysregulation and cell cycle arrest

Nanoplastics (NPs) can penetrate the intestinal barrier of organisms and accumulate in the liver, thereby inducing hepatocyte apoptosis. However, the underlying mechanisms remain incompletely elucidated. This study examined the effects of PS-NPs exposure on hepatocyte apoptosis and revealed the role of cell cycle arrest and mitophagy. The C57BL/6 mice were administered a diet containing 100 nm and 500 nm PS-NPs at a concentration of 0.1 g/kg for 180 days, respectively. TUNEL staining confirmed that 100 nm PS-NPs induced more pronounced apoptosis compared to 500 nm PS-NPs in mouse liver. Mechanistically, proteomic analysis revealed that Pdcd2l, associated with the S phase of cell cycle and apoptosis, exhibited the highest fold changes among all detected proteins in 100 nm and 500 nm PS-NPs exposure groups. Notably, the expression of Tbc1d17, Bcl2l13, and Pgam5 involved in mitophagosome formation in mouse liver was upregulated by 100 nm PS-NPs but not by 500 nm PS-NPs; moreover, mitophagosomes were observed in HepG2 cells exposed to 100 nm PS-NPs. Additionally, 100 nm PS-NPs internalized by HepG2 cells could penetrate lysosomes. The protein levels of Igf2r and Rab7a were altered, and p62 mRNA expression was increased in mouse liver, suggesting 100 nm PS-NPs, but not 500 nm PS-NPs, impaired lysosomal function and subsequently inhibited mitophagy degradation. Collectively, 500 nm PS-NPs induced Pdcd2l-mediated cell cycle arrest, thereby exacerbating hepatocyte apoptosis; while 100 nm PS-NPs not only triggered similar levels of cell cycle arrest as 500 nm PS-NPs, but also disrupted mitophagy, which was also associated with hepatocyte apoptosis.

Zinc-Mediated Endoplasmic Reticulum Stress and Metallothionein Alleviate Arsenic-Induced Cardiotoxicity in Cyprinus Carpio

Arsenic (As) is a natural component of the Earth's crust, and its inorganic form is highly toxic. The problem of As pollution in water is extremely urgent, and its impact on aquatic organisms should be widely considered. Here, 120 common carp were selected as the test subjects and were exposed to environmentally relevant concentrations of As (2.83 mg L- 1) for 30 days. Histomorphological observations showed the adverse effects of As on the heart: irregular arrangement of myocardial fibers, rupture of muscle fiber bundles, inflammatory infiltration, and hemorrhages. Mechanistically, abnormal expression of factors related to As-induced inflammation (TLR4/MYD88/NF-κB pathway), endoplasmic reticulum stress (CHOP, GRP78, ATF6, PERK, IRE1) and oxidative stress (SOD, CAT, Nrf2, HO-1) was observed. Then, we tried to find a protective agent against As-induced myocardial injury. As one of the important metal elements for maintaining cell growth and immunity, zinc (Zn, 1 mg L- 1) significantly alleviated the pathological abnormalities induced by As, and the changes in physiological and biochemical indices in response to As exposure were significantly alleviated by Zn administration, which was accompanied by the restoration of metallothionein (ZIP8, Znt1, Znt5, Znt7) and heat shock protein (HSP60, HSP70, HSP90) expression. These results suggest for the possibilty of developing Zn as a candidate therapeutic agent for As induced aquatic toxicology.

D-Limonene Alleviates Oxidative Stress Injury of the Testis Induced by Arsenic in Rat

Long-term exposure to arsenic can lead to testicular damage and lower sperm quality in males, which is mediated by increased arsenic-induced oxidative stress and other damage mechanisms. D-Limonene, which is rich in oranges, lemons, oranges, grapes and other natural fruits, can relieve doxorubicin (DOX)-induced kidney injury and CCL4-induced cardiac toxicity by inhibiting oxidative stress and inflammatory response. The antioxidant and anti-inflammatory properties of D-limonene motivate us to further explore whether it can reduce arsenic-induced testicular injury. To verify this scientific hypothesis, testicular pathology, testicular oxidative stress levels and sperm motility were determined after intervention with D-limonene in rats chronically exposed to arsenic. As expected, long-term arsenic exposure caused testicular tissue structure disturbances, increased levels of oxidative stress, and decreased sperm activation, all of which were significantly inhibited due to treatment with D-limonene. In conclusion, our data reveal a previously unproven beneficial effect of D-limonene, namely that D-limonene can inhibit arsenic-induced testicular injury, and also provide theoretical and experimental basis for the application of D-limonene in the treatment of arsenic-induced testicular injury.

Didactical approaches and insights into environmental processes and cardiovascular hazards of arsenic contaminants

Arsenic, as a metalloid, has the ability to move and transform in different environmental media. Its widespread contamination has become a significant environmental problem and public concern. Arsenic can jeopardize multiple organs through various pathways, influenced by environmental bioprocesses. This article provides a comprehensive overview of current research on the cardiovascular hazards of arsenic. A bibliometric analysis revealed that there are 376 papers published in 145 journals, involving 40 countries, 631 institutions, and 2093 authors, all focused on arsenic-related concerns regarding cardiovascular health. China and the U.S. have emerged as the central hubs of collaborative relationships and have the highest number of publications. Hypertension and atherosclerosis are the most extensively studied topics, with redox imbalance, apoptosis, and methylation being the primary mechanistic clues. Cardiovascular damage caused by arsenic includes arrhythmia, cardiac remodeling, vascular leakage, and abnormal angiogenesis. However, the current understanding is still inadequate over cardiovascular impairments, underlying mechanisms, and precautionary methods of arsenic, thus calling an urgent need for further studies to bridge the gap between environmental processes and arsenic hazards.

The effects of soil intake on the growth performance, rumen microbial community and tissue mineral deposition of German Mutton Merino sheep

Soil ingestion by livestock is common in grazing ecosystems, but few studies have been conducted to assess its effect on the animal organism. The topic is worthy of attention because these potential effects are likely to be enriched in the food chain and interfere with animal and human health. In this study, we present an indoor feeding trial conducted based on a completely randomized design to comprehensively evaluate the effects of simulated soil ingestion during grazing on nutrient digestibility, rumen fermentation, and microflora, and mineral deposition in the organs and tissues of sheep. Eighteen Mutton Merino crossbred sheep (42.7 ± 2.34 kg) were randomly allotted to three treatments and fed diets containing 0% (Control), 5% (SOIL5), and 10% (SOIL10) for 62 d, including a 7-d metabolism trial. It was found that soil intake altered the rumen fermentation in sheep, as evidenced by a decrease in total volatile fatty acids (VFA) and acetate concentrations in rumen fluid of 50.6% and 51.3%, respectively (p < 0.01), with soil proportion in the diet increased from 0% to 10%. Soil ingestion also reduced the species richness of rumen bacteria, with the relative abundance of Bacteroidetes decreasing significantly (p < 0.01), while that of Firmicutes and Proteobacteria increased considerably (p < 0.05). In terms of mineral elements deposition, higher levels of iron (Fe) were detected in the spleen and liver, and a higher concentration of copper (Cu) and zinc (Zn) in the liver were found in sheep fed a diet containing 5% soil compared to the other two groups (p < 0.05). Moreover, the concentrations of lead (Pb) in the liver and kidney, and arsenic (As) in the heart were also clearly increased after ingestion of soil (p < 0.05). Our findings indicate that although soil intake had no significant effect on the growth performance of sheep, it altered ruminal fermentation and increased the risk of excessive Fe, Pb, and As in their organism. This study supplies a theoretical basis for risk assessment of soil ingestion in grazing livestock.

Sacubitril/valsartan protects against arsenic trioxide induced cardiotoxicity in vivo and in vitro

The cardiotoxicity induced by arsenic trioxide (ATO) limits its clinical application in acute promyelocytic leukemia treatment. Sacubitril/valsartan (LCZ696) is an effective drug for the treatment of heart failure. In this study, we aimed to investigate the protective effect and mechanisms of LCZ696 against the ATO-induced cardiotoxicity in mice and H9c2 cells. We found that LCZ696 could alleviate the decrease of ejection fraction and fractional shortening induced by ATO, thereby improving mouse cardiac contractile function. LCZ696 could also reduce the myocardial enzyme, resist oxidative stress, mitigate myocardial fibrosis, and ameliorate myocardial structure, thereby alleviating myocardial damage caused by ATO. In addition, LCZ696 could significantly increase the cell viability and reduce the accumulation of reactive oxygen species in ATO-treated H9c2 cells. Besides, in vivo and in vitro studies have been found that LCZ696 could restore the expression of Bcl-2 and reduce Bax and Caspase-3 levels, inhibiting ATO-induced apoptosis. Meanwhile, LCZ696 decreased the levels of IL-1, IL-6, and TNF-α, alleviating the inflammatory injury caused by ATO. Furthermore, LCZ696 prevented NF-κB upregulation induced by ATO. Our findings revealed that LCZ696 has a considerable effect on preventing cardiotoxicity induced by ATO, which attributes to its capability to suppress oxidative stress, inflammation, and apoptosis.

Proteomics analysis in the kidney of mice following oral feeding Realgar

ETHNOPHARMACOLOGICAL RELEVANCE

Realgar, a famous traditional Chinese mineral medicine, has been toxic to the renal system. However, the underlying mechanism of Realgar nephrotoxicity is still unclear.

AIM OF THE STUDY

This study aimed to investigate the potential mechanism of Realgar-induced nephrotoxicity by using a label-free quantitative proteomic method.

MATERIALS AND METHODS

36 mice were randomly divided into four groups: Control group, 0.5-, 1.0, and 2.0 g/kg Realgar group. After one week, serum biochemical parameters and renal histopathological examination were performed. Label-free quantitative proteomics was used to identify differentially expressed proteins which were subsequently analyzed with bioinformatics methods. Western blot was utilized to verify the six representative protein expressions.

RESULTS

The results showed that 2.0 g/kg Realgar significantly increased blood urea nitrogen and induced the formation of tube cast of renal tubules, while the lower-dose of 0.5 g/kg and 1.0 g/kg Realgar showed no changes. Label-free proteomic analysis identified 3138 proteins, and 272 of those proteins were screened for significant changes in a dose-dependent manner. Functional enrichment analysis suggested that these proteins could affect the apoptotic process and oxidative stress. Representative proteins in the 2.0 g/kg Realgar group, including Cat, Bad, Cycs, Nqo1, Podxl, and Hmox1, were verified by western blot.

CONCLUSIONS

The results in this study suggest that apoptosis and oxidative stress might be related to the Realgar-induced nephrotoxicity in mice. Moreover, the strategy of proteomics could contribute to the understanding of the mechanisms of nephrotoxicity in mice exposed to Realgar.

Toxic effects of TiO2 NPs in the blood-milk barrier of the maternal dams and growth of offspring

Titanium dioxide nanoparticles (TiO₂ NPs) are amongst the most frequently used nanomaterial in everyday consumer products, and their widespread applications have raised concerns of the consequent deleterious effects on human health, particularly to vulnerable populations, such as lactating females remains elusive. Therefore, this study was initiated to investigate the detrimental effects and toxic mechanisms induced by TiO₂ NPs in maternal dams and offspring during the lactation period. Dams were randomly divided into three groups. The water (Control; Group I) and TiO₂ NPs (100 mg/kg; Group II) were orally administered from postnatal day 1-20, respectively. The results indicated that TiO₂ NPs could cause toxicity in the dams, such as pathological damages to mammary gland tissues. The excessive accumulation of TiO₂ NPs could induce oxidative stress in the mammary gland, leading to the dysfunctional blood-milk barrier; besides, TiO₂ NPs could also be transferred to offspring via breastfeeding, causing abnormal development of infant. We further accessed the possible underlying molecular mechanism; for this, we orally administered TiO₂ NPs with vitamin E (100 mg/kg; Group III). The results revealed that toxicity induced by TiO₂ NPs was rescued. Collectively, this study presented the deleterious pathological effects of oral exposure to TiO₂ NPs in the mammary gland tissues and blood-milk barrier via the production of reactive oxygen species (ROS) in dams and developmental concerns in offspring. However, the administration of VE could mitigate the toxic effects induced by the TiO₂ NPs.

A Systematic Review of the Various Effect of Arsenic on Glutathione Synthesis In Vitro and In Vivo

Background

Arsenic is a toxic metalloid widely present in nature, and arsenic poisoning in drinking water is a serious global public problem. Glutathione is an important reducing agent that inhibits arsenic-induced oxidative stress and participates in arsenic methylation metabolism. Therefore, glutathione plays an important role in regulating arsenic toxicity. In recent years, a large number of studies have shown that arsenic can regulate glutathione synthesis in many ways, but there are many contradictions in the research results. At present, the mechanism of the effect of arsenic on glutathione synthesis has not been elucidated.

Objective

We will conduct a meta-analysis to illustrate the effects of arsenic on GSH synthesis precursors Glu, Cys, Gly, and rate-limiting enzyme γ-GCS in mammalian models, as well as the regulation of p38/Nrf2 of γ-GCS subunit GCLC, and further explore the molecular mechanism of arsenic affecting glutathione synthesis.

Results

This meta-analysis included 30 studies in vivo and 58 studies in vitro, among which in vivo studies showed that arsenic exposure could reduce the contents of GSH (SMD = -2.86, 95% CI (-4.45, -1.27)), Glu (SMD = -1.11, 95% CI (-2.20,-0.02)), and Cys (SMD = -1.48, 95% CI (-2.63, -0.33)), with no statistically significant difference in p38/Nrf2, GCLC, and GCLM. In vitro studies showed that arsenic exposure increased intracellular GSH content (SMD = 1.87, 95% CI (0.18, 3.56)) and promoted the expression of p-p38 (SMD = 4.19, 95% CI (2.34, 6.05)), Nrf2 (SMD = 4.60, 95% CI (2.34, 6.86)), and GCLC (SMD = 1.32, 95% CI (0.23, 2.41)); the p38 inhibitor inhibited the expression of Nrf2 (SMD = -1.27, 95% CI (-2.46, -0.09)) and GCLC (SMD = -5.37, 95% CI (-5.37, -2.20)); siNrf2 inhibited the expression of GCLC, and BSO inhibited the synthesis of GSH. There is a dose-dependent relationship between the effects of exposure on GSH in vitro. Conclusions. These indicate the difference between in vivo and in vitro studies of the effect of arsenic on glutathione synthesis. In vivo studies have shown that arsenic exposure can reduce glutamate and cysteine levels and inhibit glutathione synthesis, while in vitro studies have shown that chronic low-dose arsenic exposure can activate the p38/Nrf2 pathway, upregulate GCLC expression, and promote glutathione synthesis.

Lipid Metabolism Alterations in a Rat Model of Chronic and Intergenerational Exposure to Arsenic

Chronic exposure to arsenic (As), whether directly through the consumption of contaminated drinking water or indirectly through the daily intake of As-contaminated food, is a health threat for more than 150 million people worldwide. Epidemiological studies found an association between chronic consumption of As and several pathologies, the most common being cancer-related disorders. However, As consumption has also been associated with metabolic disorders that could lead to diverse pathologies, such as type 2 diabetes mellitus, nonalcoholic fatty liver disease, and obesity. Here, we used ultra-performance liquid chromatography (UPLC) coupled to electrospray ionization/quadrupole time-of-flight mass spectrometry (ESI-QToF) to assess the effect of chronic intergenerational As exposure on the lipid metabolism profiles of serum from 4-month-old Wistar rats exposed to As prenatally and also during early life in drinking water (3 ppm). Significant differences in the levels of certain identified lysophospholipids, phosphatidylcholines, and triglycerides were found between the exposed rats and the control groups, as well as between the sexes. Significantly increased lipid oxidation determined by the malondialdehyde (MDA) method was found in exposed rats compared with controls. Chronic intergenerational As exposure alters the rat lipidome, increases lipid oxidation, and dysregulates metabolic pathways, the factors associated with the chronic inflammation present in different diseases associated with chronic exposure to As (i.e., keratosis, Bowen's disease, and kidney, liver, bladder, and lung cancer).

Enhanced histone H3K9 tri-methylation suppresses steroidogenesis in rat testis chronically exposed to arsenic

Arsenic poses a profound health risk including male reproductive dysfunction upon prolonged exposure. Histone methylation is an important epigenetic driver; however, its role in arsenic- induced steroidogenic pathogenesis remains obscure. In current study, we investigated the effect of histone H3K9 tri-methylation (H3K9me3) on expression pattern of steroidogenic genes in rat testis after long-term arsenic exposure. Our results revealed that arsenic exposure down-regulated the mRNA expressions of all studied steroidogenic genes (Lhr, Star, P450scc, Hsd3b, Cyp17a1, Hsd17b and Arom). Moreover, arsenic significantly increased the H3K9me3 level in rat testis. The plausible explanation of increased H3K9me3 was attributable to the up-regulation of histone H3K9me3 methyltransferase, Suv39h1 and down-regulation of demethylase, Jmjd2a. Since H3K9me3 activation leads to gene repression, we further investigated whether the down-regulation of steroidogenic genes was ascribed to the increased H3K9me3 level. To elucidate this, we determined the H3K9me3 levels in steroidogenic gene promoters, which also showed significant increase of H3K9me3 in the investigated regions after arsenic exposure. In conclusion, arsenic exposure suppressed the steroidogenic gene expression by activating H3K9me3 status, which contributed to steroidogenic inhibition in rat testis.