Nano Copper Induces Apoptosis in PK-15 Cells via a Mitochondria-Mediated Pathway

Balancing Risks versus Benefits: Vitamin C Therapy versus Copper Oxide Nanoparticles Toxicity in Albino Rats' Submandibular Salivary Gland

OBJECTIVES

 This study aimed to examine the suppressive effect of the natural antioxidant vitamin C (VC) against submandibular gland toxicity induced by copper oxide nanoparticles (CuO-NPs).

MATERIALS AND METHODS

 Three groups of 30 mature male albino rats (4 weeks old) weighing between 150 and 200 g were selected. The rats were randomly assigned for 6 weeks to receive: intraperitoneal injection (IP) of vehicle (control group); IP of 2.5 mg/kg body weight (bw) of CuO-NPs (CuO-NPs group); and IP of 2.5 mg/kg bw of CuO-NPs, combined with a daily oral dose of 100 mg/kg bw of VC in drinking water via gavage (CuO-NPs/VC group). The rats were euthanized, and their submandibular glands were dissected for histological evaluation, including hematoxylin and eosin staining and immunohistochemistry for Ki-67 and caspase-3.

STATISTICAL ANALYSIS

 The area expression for Ki-67 and caspase-3 was statistically analyzed using GraphPad Prism. Following analysis of variance analysis, Tukey's post hoc was used for multiple comparisons. The significance level was set at p < 0.05.

RESULTS

 CuO-NPs caused significant cytotoxic effects on submandibular salivary gland cells in albino rats. This led to an increase in Ki-67 and caspase-3 levels compared with the control group. VC administration improved tissue histology and reduced Ki-67 and caspase-3 levels in the VC/CuO-NPs group compared with rats treated with CuO-NPs alone.

CONCLUSION

 The study revealed significant cytotoxic effects of CuO-NPs on the submandibular salivary gland of albino rats. VC effectively mitigated these toxic effects, suggesting its potential as a readily available antioxidant.

Features of the response to subchronic low-dose exposure to copper oxide nanoparticles in rats

Copper is an essential trace element for human health and, at the same time, a major industrial metal widely used both in its elemental form and in compounds. We conducted a dose-dependent assessment of the response of outbred albino male rats to subchronic low-dose exposure to copper oxide nanoparticles administered intraperitoneally at cumulative doses of 18 and 36 mg/kg during 6 weeks to exposure groups 1 and 2, respectively. We observed disorders at different levels of organization of the body in the exposed animals, from molecular to organismal. The observed decrease in the activity of succinate dehydrogenase in nucleated blood cells gave evidence of impaired bioenergetics processes. In view of the results of the metabolomics analysis, we assume mitochondrial damage and contribution of apoptotic processes to the pathology induced by copper poisoning. We also assume neurodegenerative effects based on the assessed morphological parameters of the nervous system, results of behavioral tests, and a decreased level of expression of genes encoding NMDA receptor subunits in the hippocampus. The hepatotoxic effect noted by a number of metabolomics-based, biochemical, and cytological indicators was manifested by the impaired protein-synthesizing function of the liver and enhanced degenerative processes in its cells. We also observed a nephrotoxic effect of nanosized copper oxide with a predominant lesion of proximal kidney tubules. At the same time, both doses tested demonstrated such positive health effects as a statistically significant decrease in the activity of alkaline phosphatase and the nucleated blood cell DNA fragmentation factor. Judging by the changes observed, the cumulative dose of copper oxide nanoparticles of 18 mg/kg body weight administered intraperitoneally approximates the threshold one for rats. The established markers of health impairments may serve as a starting point in the development of techniques of early diagnosis of copper poisoning.

Effects of Long-Term Exposure to Copper on Mitochondria-Mediated Apoptosis in Pig Liver

Copper (Cu) is listed as one of the main heavy metal pollutants, which poses potential health risks to humans. Excessive intake of Cu has shown toxic effects on the organs of many animals, and the liver is one of the most important organs to metabolize it. In this study, pigs, the mammal with similar metabolic characteristics to humans, were selected to assess the effects of long-term exposure to Cu on mitochondria-mediated apoptosis, which are of great significance for studying the toxicity of Cu to humans. Pigs were fed a diet with different contents of Cu (10, 125, and 250 mg/kg) for 80 days. Samples of blood and liver tissue were collected on days 40 and 80. Experimental results demonstrated that the accumulation of Cu in the liver was increased in a dose-dependent and time-dependent manner. Meanwhile, the curve of pig's body weight showed that a 125 mg/kg Cu diet promoted the growth of pigs during the first 40 days and then inhibited it from 40 to 80 days, while the 250 mg/kg Cu diet inhibited the growth of pigs during 80 days of feeding. Additionally, the genes and protein expression levels of Caspase-3, p53, Bax, Bak1, Bid, Bad, CytC, and Drp1 in the treatment group were higher than that in the control group, while Bcl-2, Bcl-xL, Opa1, Mfn1, and Mfn2 were decreased. In conclusion, these results indicated that long-term excessive intake of Cu could inhibit the growth of pigs and induced mitochondria-mediated apoptosis by breaking the mitochondrial dynamic balance. Synopsis: Long-term exposure to high doses of Cu could lead to mitochondrial dysfunction by breaking the mitochondrial dynamic balance, which ultimately induced mitochondria-mediated apoptosis in the liver of pigs. This might be closely related to the growth inhibition and liver damage in pigs.

Potential indicators of mitochondrial structure and function

Mitochondria regulate a range of important physiological and biochemical cellular processes including apoptotic cell death, energy production, calcium homeostasis, oxidative stress, and lipid metabolism. Given their role as the 'engines' of cells, their dysfunction is associated with a variety of disease states. Exploring the relationship between mitochondrial function and disease can reveal the mechanism(s) of drug activity and disease pathology. In this review, we summarized the methods of evaluating the structure and function of mitochondria, including the morphology, membrane fluidity, membrane potential, opening of the membrane permeability transition pore, inner membrane permeabilization, mitochondrial dynamics, mitophagy, oxidative stress, energy metabolism-related enzymes, apoptotic pathway related proteins, calcium concentration, DNA copy number, oxygen consumption, β-oxidation-related genes and proteins, cardiolipin content, and adenosine triphosphate content. We believe that the information presented in this review will help explore the pathological processes of mitochondria in the occurrence and development of diseases, as well as the activity and mechanism of drugs, and the discovery of new drugs.

Chronic tribasic copper chloride exposure induces rat liver damage by disrupting the mitophagy and apoptosis pathways

Despite the fact that copper (Cu) is a vital micronutrient to maintain body function, high doses of Cu through environmental exposure damage various organs, especially the liver, which is the main metabolic organ. To investigate the influence of long-term Cu-induced toxicity on mitophagy and apoptosis in rat liver, 96 seven-month-old male Sprague-Dawley rats were fed TBCC for 24 weeks. The results revealed that exposure to high Cu concentrations could promote oxidative stress liver injury by increasing the hepatic function index (ALT, AST and ALP) and MDA content, while reducing the activity of antioxidant enzymes (T-SOD, GSH-Px and CAT) related to oxidative stress. Consistent with histopathological observations, proper dietary Cu (15-60 mg/kg) could improve antioxidant stress levels and induce a dose-dependent increase in the mRNA expression of mitophagy-related genes, whereas a high Cu concentration (120 mg/kg) could cause severe liver impairment and ultrastructural changes and a reduction in mitophagosomes, accompanied by downregulation of Atg5, Beclin1, Pink1, Parkin, NIX, P62 and LC3B. The expression of apoptosis-related genes (Bax, Bax/Bcl-2, Caspase3, Cytc and p53) and proteins (Caspase3 and p53) was upregulated with the addition of dietary Cu. The results demonstrated that an appropriate dose of TBCC could improve liver function by promoting mitophagy and Cu enzymes that play antioxidative roles, while the accumulation of excess Cu could induce liver lesions by enhancing apoptosis and inhibiting mitophagy pathways.

Mitochondrial dysfunction resulting from the down-regulation of bone morphogenetic protein 5 may cause microtia

Background

Bone morphogenetic protein 5 (BMP5) has been identified as one of the important risk factors for microtia; however, the link between them has yet to be clarified. In this study, we aimed to demonstrate the relationship of BMP5 with mitochondrial function and investigate the specific role of mitochondria in regulating microtia development.

Methods

BMP5 expression was measured in auricular cartilage tissues from patients with and without microtia. The effects of BMP5 knockdown on cellular function and mitochondrial function were also analyzed in vitro. Changes in genome-wide expression profiles were measured in BMP5-knockdown cells. Finally, the specific impact of BMP5 down-regulation on mitochondrial fat oxidation was analyzed in vitro.

Results

BMP5 expression was down-regulated in the auricular cartilage tissues of microtia patients. BMP5 down-regulation inhibited various cellular functions in vitro, including cell proliferation, mobility, and cytoactivity. The functional integrity of mitochondria was also damaged, accompanied by a decrease in mitochondrial membrane potential, reactive oxygen species (ROS) neutralization, and reduced adenosine triphosphate (ATP) production. Carnitine O-palmitoyltransferase 2 and diacylglycerol acyltransferase 2, two of the key regulators of mitochondrial lipid oxidation, were also found to be decreased by BMP5 down-regulation.

Conclusions

Down-regulation of BMP5 affects glycerolipid metabolism and fatty acid degradation, leading to mitochondrial dysfunction, reduced ATP production, and changes in cell function, and ultimately resulting in microtia. This research provides supporting evidence for an important role of BMP5 down-regulation in affecting mitochondrial metabolism in cells, and sheds new light on the mechanisms underlying the pathogenesis of microtia.

In vitro cytotoxicity study of superparamagnetic iron oxide and silica nanoparticles on pneumocyte organelles

Inhalation is the main route of nanoparticles (NP) exposure during manufacturing. Although many mechanisms of toxicity have been described, the interaction of NP with relevant pneumocytes organelles is not widely understood. Considering that the physicochemical properties of NP influence their toxicological responses, the objective of this study was to evaluate whether exposure to different NP, crystalline Fe₃O₄ NP and amorphous SiO₂ NP could alter pneumocytes organelles in alveolar epithelial cells. To achieve this goal, cell viability, ultrastructural changes, lysosomal damage, mitochondrial membrane potential (MMP), lipid droplets (LD) formation and cytokines production were evaluated by MTT, electron microscopy, lysotracker red staining, JC-1, Oil Red staining and Milliplex® assay respectively. Both NP were observed within lamellar bodies (LB), lysosomes, and cytoplasm causing morphological changes. Exposure to SiO₂ NP at 6 h induced lysosomal activation, but not Fe₃O₄ NP. MMP decreased and LD increased at the highest concentrations after both NP exposure. Pro-inflammatory cytokines were released only after SiO₂ NP exposure at 48 h. These results indicate that SiO₂ NP have a greater impact than Fe₃O₄ NP on organelles responsible for energy, secretion, degradation and metabolism in pneumocytes leading to the development of respiratory disorders or the exacerbation of preexisting conditions. Therefore, the established biocompatibility for amorphous NP has to be reconsidered.

Integration of transcriptomic and metabolomic data reveals metabolic pathway alteration in mouse spermatogonia with the effect of copper exposure

Copper is a widespread heavy metal in environment and has toxic effects when exposed. However, study of copper-induced male reproductive toxicity is still insufficient to report, and the underlying mechanisms are unknown. Keeping in view, RNA-Seq and metabolomic were performed to identify metabolic pathways that were distressed in mouse spermatogonia with the effect of copper sulfate, and the integrated analysis of the mechanism of copper administered GC-1 cells from metabolomic and transcriptomic data. Our results demonstrated that many genes and metabolites were regulated in the copper sulfate-treated cells. The differential metabolites analysis showed that 49 and 127 metabolites were significantly different in ESI+ and ESI- mode, respectively. Meanwhile, a total of 2813 genes were up-regulated and 2488 genes were down-regulated in the treatment groups compared to those in the control groups. Interestingly, ophthalmic acid and gamma glutamylleucine were markedly increased by copper treatment in two modes. By integrating with transcriptomic and metabolomic data, we revealed that 37 and 22 most related pathways were over-enriched in ESI+ and ESI- mode, respectively. Whereas, amino acid biosynthesis and metabolism play essential role in the potential relationship between DEGs and metabolites, which suggests that amino acid biosynthesis and metabolism may be the major metabolic pathways disturbed by copper in GC-1 cells. This study provides important clues and evidence for understanding the mechanisms responsible for copper-induced male spermatogenesis toxicity, and useful biomarkers indicative of copper exposure could be discovered from present study.

Comparative Toxicological Effects of Biologically and Chemically Synthesized Copper Oxide Nanoparticles on Mice

Introduction

Copper oxide nanoparticles (CuO-NPs) are widely used as feed additives for livestock and poultry and implicated in many biomedical applications; however, overload of copper NPs induces various toxicological changes and dysfunction of animal’s organs. Thus, this study was designed to evaluate the comparative toxicological effects of biologically and chemically synthesized CuO-NPs on mice.

Methods

Transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) were used to characterize the sizes, shapes and functional groups of CuO-NPs. Forty-five mice were randomly allocated into three groups. Control group received distilled water. The second group was administered a single dose of biologically synthesized CuO-NPs (500 mg/kg bw) orally. The third group was administered a single dose of chemically synthesized CuO-NPs (500 mg/kg bw) orally.

Results

TEM revealed that biologically synthesized NPs were spherical in shape, whereas chemically synthesized NPs were spherical or elongated in shape. XRD showed that the size of biologically synthesized NPs ranged from 4.14 to 12.82 nm and that of chemically synthesized NPs ranged from 4.06 to 26.82 nm. FT-IR spectroscopy indicated that the peaks appeared between 779 cm⁻¹ and 425 cm⁻¹ in biologically synthesized NPs and between 858 cm⁻¹ and 524 cm⁻¹ in chemically synthesized NPs were for Cu-O nanostructure. Four mice died due to administration of biologically synthesized CuO-NPs. Both biologically and chemically synthesized CuO-NPs induced leukocytosis, elevated serum activities of alanine aminotransferase and aspartate aminotransferase and serum levels of urea and creatinine and increased P53 mRNA and caspase-3 protein expressions in hepatic tissues. Moreover, CuO-NPs induced degenerative and necrotized changes in hepatic, renal and splenic tissues. Biochemical, apoptotic and pathological changes were more serious in mice administered with biologically synthesized CuO-NPs.

Conclusion

This study indicated that a high dose of biologically and chemically synthesized CuO-NPs induced adverse effects on hepatic, renal and splenic tissues. At the same dose level, the biologically synthesized CuO-NPs evoked more potent toxic effects than the chemically synthesized CuO-NPs.

Long-term exposure to copper induces autophagy and apoptosis through oxidative stress in rat kidneys

Copper (Cu) is an essential trace element for most organisms. However, excessive Cu can be highly toxic. The purpose of this study was to elucidate the mechanism underlying Cu toxicity in the kidneys of rats after treatment with CuCl₂ (15 [control], 30, 60, or 120 mg/kg in the diet) for 180 days. Histological and ultrastructural changes, antioxidant enzyme activity, and the mRNA and protein levels of apoptosis and autophagy-related genes were measured. The results showed that Cu exposure led to significant accumulation of copper in kidneys and disorganized kidney morphology. The activities of total anti-oxidation capacity (T-AOC) and superoxide dismutase (SOD) in the kidneys decreased significantly, while the malondialdehyde (MDA) content increased. Furthermore, excessive Cu markedly upregulated the expression of autophagy and apoptosis-related genes (LC3A, LC3B, ATG-5, Beclin-1, Caspase3, CytC, P53, Bax), but downregulated the expression of P62, mTOR and BCL-2. Moreover, the LC3B/LC3A, ATG-5, Beclin-1, P53, Caspase3 proteins were up-regulated while P62 was down-regulated in the kidney tissues of the treatment groups. Overall, these findings provide strong evidence that excess Cu can trigger autophagy and apoptosis via the mitochondrial pathway by inducing oxidative stress in rat kidneys.

Silver Ions as a Tool for Understanding Different Aspects of Copper Metabolism

In humans, copper is an important micronutrient because it is a cofactor of ubiquitous and brain-specific cuproenzymes, as well as a secondary messenger. Failure of the mechanisms supporting copper balance leads to the development of neurodegenerative, oncological, and other severe disorders, whose treatment requires a detailed understanding of copper metabolism. In the body, bioavailable copper exists in two stable oxidation states, Cu(I) and Cu(II), both of which are highly toxic. The toxicity of copper ions is usually overcome by coordinating them with a wide range of ligands. These include the active cuproenzyme centers, copper-binding protein motifs to ensure the safe delivery of copper to its physiological location, and participants in the Cu(I) ↔ Cu(II) redox cycle, in which cellular copper is stored. The use of modern experimental approaches has allowed the overall picture of copper turnover in the cells and the organism to be clarified. However, many aspects of this process remain poorly understood. Some of them can be found out using abiogenic silver ions (Ag(I)), which are isoelectronic to Cu(I). This review covers the physicochemical principles of the ability of Ag(I) to substitute for copper ions in transport proteins and cuproenzyme active sites, the effectiveness of using Ag(I) to study copper routes in the cells and the body, and the limitations associated with Ag(I) remaining stable in only one oxidation state. The use of Ag(I) to restrict copper transport to tumors and the consequences of large-scale use of silver nanoparticles for human health are also discussed.

Inhibition of Caspase-1-dependent pyroptosis attenuates copper-induced apoptosis in chicken hepatocytes

The purpose of this study was to investigate the effects of copper (Cu) on hepatocyte pyroptosis and the relationship between pyroptosis and apoptosis in the mechanisms of Cu toxicity. Primary chicken hepatocytes were cultured in different concentrations of Cu sulfate (CuSO₄) (0, 10, 50, and 100 μM), N-acetylcysteine (NAC) (1 mM), and Z-YVAD-fluoromethylketone (Z-YVAD-FMK) (10 μM) for 24 h, and the combination of Cu and NAC or Z-YVAD-FMK for 24 h. Cellular morphology and function, cell viability, mitochondria membrane potential (MMP), apoptosis rate, mRNA expression of pyroptosis-related and apoptosis-related genes, and Caspase-1, Caspase-3 proteins expression were determined. These results indicated that Cu markedly induced the mRNA expression of pyroptosis-related genes (Caspase-1, IL-1β, IL-18, and NLRP3) and Caspase-1 protein expression. Furthermore, contents of Caspase-1, IL-1β, and IL-18 in the supernatant fluid of culture hepatocytes were significantly increased in hepatocytes. NAC relieved excess Cu-caused the changes of above genes and proteins. Additionally, Z-YVAD-FMK, caspase-1 inhibitor, which attenuated Cu-induced the increased lactic dehydrogenase (LDH), aspartate amino transferase (AST), alanine aminotransferase (ALT) activities. Furthermore, treatment with Cu and Z-YVAD-FMK could down-regulate the mRNA levels of Caspase-3, Bak1, Bax, and CytC and Caspase-3 protein expression, up-regulate the mRNA expression of Bcl2, increase the MMP and reduce cell apoptosis compared to treatment with Cu in hepatocytes. Collectively, these finding evidenced that excess Cu induced pyroptosis by generating ROS in hepatocytes, and the inhibition of Caspase-1-dependent pyroptosis might attenuate Cu-induced apoptosis.

Metabonomic analysis of the hepatic injury suffer from hexavalent chromium poisoning in broilers

Chromium is used in daily life and has a wide range of functions. It plays an important role in protein synthesis and carbohydrate and lipid metabolism. Chromium is found in trivalent Cr(III) and hexavalent Cr(VI) form; Cr(III) is relatively stable and intimately participates with many phenomena of metabolisms. Whereas, Cr(VI) is toxic, which results in growth inhibition and leading to changes in components of antioxidant systems as well as secondary metabolites. However, the molecular mechanism that is involved in Cr (VI)-induced hepatotoxicity is still unclear. For this purpose, 40 chickens were randomly assigned into two groups: the normal group (feeding the basic diet and clear water), the chromium group (16%LD₅₀, 74.24 mg/kg/day K₂Cr₂O₇ ). The samples were subjected to pathological examination and UHPLC-QE-MS non-target metabolomics method for metabolomics analysis of broiler liver using principal component analysis (PCA) and partial least squares discriminant analysis (OPLS-DA). The central venous cells of the broiler liver in the chromium poisoning group showed turbidity and flaky necrosis, nuclear condensation, nuclear rupture, and even nuclear dissolution. The differential metabolite analysis between the chromium poisoning and the control group showed that 32 differential metabolites were upregulated and 15 were downregulated in positive ion mode. Whereas,17 differential metabolites were downregulated, and 35 were downregulated in negative ion mode (P ≤ 0.05). The potential marker substances are oleic acidamide, farnesylacetone, betaine, taurine, choline, and galactinol. Additionally, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways showed that the lipid metabolism, carbohydrate metabolism, nucleotide metabolism, amino acid metabolism, energy metabolism, membrane transport, digestive system, and nervous system were the most important metabolic pathways in the liver. This study provides a theoretical basis for the future understanding of the pathogenesis of chromium poisoning and a new insight of the subsequent molecular mechanism of chromium hepatotoxicity.

Effect of Anacardic Acid against Thiram Induced Tibial Dyschondroplasia in Chickens via Regulation of Wnt4 Expression

Simple Summary

This study evaluated the ameliorating effect of anacardic acid (AA) in tibial dyschondroplasia (TD) chickens. Our results showed that AA can increase the feed conversion ratio, improve the weight, length and width of the tibia. AA administration restored the antioxidant parameters significantly (p < 0.05). The gene expression analysis revealed a decrease in wingless-type member 4 (Wnt4) expressions in TD chickens as compared to the control group, while AA treatment up-regulated the Wnt4 expression. The present study demonstrates that the AA plays an important role to prevent the lameness and restore the size of the tibial growth plate of chickens by regulating the expression of Wnt4.

Abstract

Tibial dyschondroplasia (TD) is a tibia bone problem in broilers. Anacardic acid (AA) is a traditional Chinese medicine, which is commonly used to treat arthritis in human. The purpose of the present study is to investigate the effect of AA against TD. A total of 300 day-old poultry birds were equally divided and distributed into three different groups: Control, TD and AA groups. The results showed that the feed conversion ratio was significantly lower in the TD group than control chickens. The tibia bone parameters including weight, length and width were of low quality in TD chickens, while the width of the tibial growth plate was enlarged remarkably. Whereas, in the AA treatment group, the tibia bone parameters showed improvement and tend to return to normal. The antioxidant parameters level of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), total and antioxidant capacity (T-AOC) was significantly decreased, while malondialdehyde (MDA) level was increased significantly in TD affected chickens. AA administration restored the antioxidant parameters significantly. The gene expression revealed a decrease in Wnt4 expression in TD chickens as compared to control chickens, while AA treatment up-regulated the Wnt4 expression. The present study demonstrates that the AA plays an important role to prevent the lameness and restore the size of tibial growth plate of chickens by regulating the expression of Wnt4.

Effect of tetramethyl thiuram disulfide (thiram) in relation to tibial dyschondroplasia in chickens

Tetramethyl thiuram disulfide (thiram) is one of the important pesticides, which is extensively used in agriculture, but if it is combined with the cell membrane, then it causes membrane damage, bone morphogenic inactivation, and inhibited angiogenesis. Thiram has been considered a common cause of tibial dyschondrolplasia (TD) in various avian species, because it becomes the part of feed due to environmental contamination and its overuse in agriculture as pesticides or fungicide. However, there is no systematic study on the changes of the correlation indexes with toxic effect of the thiram in chickens. Therefore, we evaluated the toxic effects of thiram on growth performance of chickens, viscera organ index, pathological changes in tissue, and gene expression associated with osteoblast differentiation, vascularization, and tibial bone development. For this study, 1-day chickens (n = 300) were randomly distributed into two equal groups, control group (normal basal diet) and thiram group (adding thiram 40 mg/kg in basal diet). The result presented that thiram group chickens were looking unhealthy, lazy, and showing clinical symptoms like lameness. Thiram treatment significantly reduced the performance of chickens, liver index, and tibial length compared with control group. The toxic effect of thiram increased the visceral organ index (spleen and cardiac), tibia index, and TD severity considerably. It also increased serum Ca²⁺ and P³⁺ concentration and decreased tibial density compared to control chickens but the difference was not significant. Histopathology of tibia and liver showed that there were severe lesions due to toxic effect of thiram. Furthermore, HIF-1α and VEGF antibody localizations were increased and WNT4 localization was reduced significantly in immunohistochemical analysis. This systemic study of toxic effects of thiram in chicken concluded that thiram reduced the growth performance of chickens through decreasing liver index, whereas increasing kidney, cardiac, and spleen index, and induced TD by changing the expressions of VEGF, HIF-1α, and WNT4.

Transcriptome analysis reveals the molecular mechanism of hepatic metabolism disorder caused by chromium poisoning in chickens

Chromium (Cr) is one of the most important environmental pollutants which are released into the environment due to their wide usage in numerous industries. The excess of Cr (VI) can induce hepatotoxicity, while the molecular mechanism that is involved in Cr (VI)-induced hepatotoxicity is unclear. We demonstrated the induction of chromium poisoning model in chickens to identify the differentially expressed genes (DEGs), and their functions were analyzed under different physiological and pathological conditions. Histopathological examination and transcriptome data for chromium-poisoned livers and control livers were annotated with Illumina® HiSeq 2000. The histopathological examination in chromium poisoning groups showed diapedesis, hemolysis, degeneration, nucleus pycnosis, and central phlebectasia in the liver. A total of 334 genes were upregulated and 509 genes were downregulated. The most strongly upregulated genes were HKDC1, DDX4, ACACA, FDFT1, CYYR1, PPP1R3C, and SLC16A14, while the most downregulated genes were MYBPC3, CCKAR, PCK1, and CPT1A. A Gene Ontology (GO) term with the highest enrichment of DEGs is small molecule metabolic process. In cell component domain, the term with the highest enrichment is extracellular matrix. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways showed that glucose metabolism, lipid metabolism, and protein metabolism were the most important metabolic pathways in the liver. The current study first time provides important clues and evidence for identifying the differentially expressed genes in livers due to Cr (VI)-induced liver injury in chickens.

Effect of tetramethylpyrazine on tibial dyschondroplasia incidence, tibial angiogenesis, performance and characteristics via HIF-1α/VEGF signaling pathway in chickens

Tibial dyschodroplasia (TD) is a most common pathological condition in many avian species that is characterized by failure of growth plate (GP) modeling that leads to the persistence of avascular lesion in the GP. Tetramethylpyrazine (TMP) is widely used to treat neurovascular disorders and pulmonary hypertension, but no report is available about promoting effect of TMP against TD. Therefore, a total of 210 broiler chicks were equally divided into three groups; Control, TD and TMP. During the experiment mortality rate, chicken performance indicators (daily weight, average daily feed intake, average daily weight gain and feed conversion ratio), tibia bone indicators (weight, length, width of tibial and the size of GP) in addition to gene expression of HIF-1α and VEGF were examined. The results showed that TMP administration restore the GP width, increase growth performance, and mitigated the lameness in broiler chickens. The expression of HIF-1α and VEGF increased significantly in TD affected thiram induced chicks. Whereas, TMP treatment down-regulated HIF-1α and VEGF genes and proteins expressions. The present study demonstrates that the TMP plays an important role in angiogenesis during the impairment and recovery of GP in TD via regulation of the HIF-1α/VEGF signaling pathway in chickens.