Calcium alleviates fluoride-induced kidney damage via FAS/FASL, TNFR/TNF, DR5/TRAIL pathways in rats.

Long-term excessive intake of fluoride (F) can cause osseous and non-osseous damage. The kidney is the main fluoride excretion organ of the body. This study aimed to explore whether dietary calcium (Ca) supplementation can alleviate kidney damage caused by fluorosis and to further investigate the effects of Ca on the mitigation mechanism of renal cell apoptosis triggered by F. We evaluated the histopathological structure, renal function indicators, and gene and protein expression levels of death receptor-mediated apoptosis pathways in Sprague Dawley (SD) rats treated with sodium fluoride (NaF) and/or calcium carbonate (CaCO3) for 120 days. The results showed that 100 mg/L NaF induced kidney histopathological injury and apoptosis, increased the concentrations of Creatinine (CRE), uric acid (UA), blood urea nitrogen (BUN), potassium (K), phosphorus (P) and F (p < 0.05), and decrease the level of serum magnesium (Mg) (p < 0.05). Moreover, NaF increased the mRNA and protein expression levels of Fas cell surface death receptor (FAS), tumor necrosis factor (TNF), TNF-related apoptosis-inducing ligand (TRAIL), Caspase 8, Caspase 3 and poly ADP-ribose polymerase (PARP) (p < 0.01), which finally activated the death receptor pathway. Inversely, Ca supplementation reversed the decrease of CRE, BUN, UA, F and P levels induced by F, alleviated histopathological damage and apoptosis, and reduced the gene and protein expression levels of death receptor pathway-related markers. In conclusion, 1% Ca alleviates F-induced kidney apoptosis through FAS/FASL, TNFR/TNF, DR5/TRAIL signaling pathways.

Co-exposure to fluoride and sulfur dioxide on histological alteration and DNA damage in rat brain.

Fluoride (F) and sulfur dioxide (SO2 ) are the two common environmental contaminants that are associated with neurotoxicity. The present study was conducted to explore individual and combined exposure effects of F and SO2 on histological alteration and DNA damage in rat brain. For this, male Wistar albino rats were exposed to sodium fluoride (100 mg/L NaF) and sulfur dioxide (39.3 mg/m3 ) individually and in combination for 8 weeks. Histological alteration in brain is evaluated by hematoxylin-eosin staining, showed shrunken neurons, darkly stained small nucleus and decreased cell numbers in F and SO2 exposed groups. The effect of F and SO2 on DNA damage was assessed by comet assay. The results showed an increase in ratio of tailing and tail length in F or/and SO2 administered rats. In addition, the proportion of grade II and III were also increased in individual and combined exposed groups. Compared with the individual exposure, the proportion the grade III was significantly high in combined exposure, suggesting a synergistic effect of F and SO2 . These results indicate that the brain was more susceptible to the toxic effects of F and SO2 . And combined exposure to these pollutants can lead more pronounced toxic effects on brain.

Fluoride induces apoptosis and autophagy through the IL-17 signaling pathway in mice hepatocytes.

Previous studies have reported that excessive fluoride exposure induced liver damage. However, the underlying mechanism of fluoride-induced hepatic toxicity is still unclear. Hence, this study was aimed to evaluate the fluoride-induced apoptosis, autophagy, and IL-17 signaling pathway-related genes to explore the possible mechanisms of NaF-induced liver injury in mice. For this, 48 male mice were allotted randomly to four groups, treated with deionized water, 25, 50, 100 mg/L NaF for 150 days continuously. Our results suggested that treatment with NaF decreased the PAS staining-positive area, with a concomitant increase in liver score, and serum ALT and AST levels which indicated that NaF induced the liver injury. In addition, the qRT-PCR, immunohistochemistry, and western blotting results indicated that NaF exposure activated IL-17 signaling, apoptosis, and autophagy pathways. In summary, these results suggested that NaF induced apoptosis and autophagy in liver by activating the IL-17 signaling pathway, eventually leading to impaired liver function.

Alterations in epididymal proteomics and antioxidant activity of mice exposed to fluoride.

It is well known that high fluoride results in low fertility. Epididymis is the important place for spermatozoa maturation, which is essential for successful fertilization. In the previous studies, fluoride was reported to damage the epididymal structure of mouse and rabbit. However, the mechanism underlying sodium fluoride (NaF)-induced epididymal toxicity has not yet been well elucidated. The aim of this study is to explore the global protein alterations in epididymis of mice exposed to NaF using the iTRAQ technique. Results showed that 211 proteins were differentially expressed in both 25 and 100 mg/L NaF groups. Some of them have been proved to be important for reproduction, such as low-density lipoprotein receptor-related protein 2 (Lrp2), cytochrome c, testis-specific (Cyct), sorbitol dehydrogenase (Sord), glutathione S-transferases (GSTs), acrosin, beta-defensin 126, cysteine-rich secretory protein (Crisp) 1, and Crisp2. Gene ontology (GO) analysis suggested cellular process, organelle and catalytic activity account for high percent and number of differentially expressed proteins. 171 pathways were found after the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, among which the representative maps, such as ribosome, focal adhesion, and phagosome, were involved. Different functional categories post-translational modification, protein turnover, chaperones; translation, ribosomal structure and biogenesis; cytoskeleton; energy production and conversion are implicated in the Cluster of Orthologous Groups (COG) of proteins analysis. Subsequently, the effect of NaF on the antioxidant activity in epididymis, especially glutathione and glutathione-related enzymes, was evaluated. Results exhibited high fluoride caused low total antioxidant capacity (T-AOC), high methane dicarboxylic aldehyde (MDA), decreased reduced glutathione (GSH), and the glutathione-related enzymes [GSH peroxidase (GPx), GSH reductase (GR), and GSH S-transferase (GST)] changes in activity, protein, and mRNA expressions. In summary, NaF decreased the antioxidant activity of epididymis, especially glutathione and glutathione-related enzymes, as well as iTRAQ results, providing new explanations for the low sperm quality induced by fluoride.

Arsenic induces autophagy in developmental mouse cerebral cortex and hippocampus by inhibiting PI3K/Akt/mTOR signaling pathway: involvement of blood-brain barrier's tight junction proteins.

For the past decade, there has been an increased concern about the health risks from arsenic (As) exposure, because of its neurotoxic effects on the developing brain. The exact mechanism underlying As-induced neurotoxicity during sensitive periods of brain development remains unclear, especially the role of blood-brain barrier's (BBB) tight junction (TJ) proteins during As-induced neurotoxicity. Here, we highlight the involvement of TJ proteins in As-induced autophagy in cerebral cortex and hippocampus during developmental periods [postnatal day (PND) 21, 28, 35 and 42]. Here, the administration of arsenic trioxide (As2O3) at doses of 0.15 mg or 1.5 mg or 15 mg As2O3/L in drinking water from gestational to lactational and continued to the pups till PND42 resulted in a significant decrease in the mRNA expression levels of TJ proteins (Occludin, Claudin, ZO-1 and ZO-2) and Occludin protein expression level. In addition, As exposure significantly decreased PI3K, Akt, mTOR, and p62 with a concomitant increase in Beclin1, LC3I, LC3II, Atg5 and Atg12. Moreover, As exposure also significantly downregulated the protein expression levels of mTOR with a concomitant upregulation of Beclin 1, LC3 and Atg12 in all the developmental age points. However, no significant alterations were observed in low and medium dose-exposed groups of PND42. Histopathological analysis in As-exposed mice revealed decreased number of pyramidal neurons in hippocampus; and neurons with degenerating axons, shrinkage of cells, remarkable vacuolar degeneration in cytoplasm, karyolysis and pyknosis in cerebral cortex. Ultrastructural analysis by transmission electron microscopy revealed the occurrence of autophagosomes and vacuolated axons in the cerebral cortex and hippocampus of the mice exposed to high dose As at PND21 and 42. The severities of changes were found to more persist in the cerebral cortex than in the hippocampus of As-exposed mice. Finally, we conclude that the leaky BBB in cerebral cortex and hippocampus may facilitate the transfer of As and induces autophagy by inhibiting PI3K/Akt/mTOR signaling pathway in an age-dependent manner, i.e., among the four different developmental age points, PND21 animals were found to be more vulnerable to the As-induced neurotoxicity than the other three age points.

Abnormal spermatogenesis following sodium fluoride exposure is associated with the downregulation of CREM and ACT in the mouse testis.

cAMP response element modulator (CREM) is involved in regulating gene expression in normal spermatogenesis. The transcriptional activity of CREM is partly regulated by activator of CREM in the testis (ACT). To investigate the effects of different concentrations of sodium fluoride (NaF) on the gene and protein expression of CREM and ACT in the mouse testis, sexually mature male Kunming mice were exposed to 50, 100, or 150 mg/L NaF in their drinking water for 90 days. NaF reduced the sperm count and viability and increased the percentage of malformed sperm in a dose-dependent manner. The mRNA expression of CREM and ACT was markedly downregulated in the NaF-treated groups. Furthermore, immunohistochemistry revealed that CREM and ACT proteins were decreased significantly in the 50, 100, and 150 mg/L NaF-treated groups compared to the control group. These findings indicate that the decreased gene and protein expression of CREM and ACT in the testis is associated with an impairment of reproductive functions by NaF.

Brain-Derived Neurotrophic Factor - The Protective Agent Against Neurological Disorders.

The burden of neurological illnesses on global health is significant. Our perception of the molecular and biological mechanisms underlying intellectual processing and behavior has significantly advanced over the last few decades, laying the groundwork for potential therapies for various neurodegenerative diseases. A growing body of literature reveals that most neurodegenerative diseases could be due to the gradual failure of neurons in the brain's neocortex, hippocampus, and various subcortical areas. Research on various experimental models has uncovered several gene components to understand the pathogenesis of neurodegenerative disorders. One among them is the brain-derived neurotrophic factor (BDNF), which performs several vital functions, enhancing synaptic plasticity and assisting in the emergence of long-term thoughts. The pathophysiology of some neurodegenerative diseases, including Alzheimer's, Parkinson's, Schizophrenia, and Huntington's, has been linked to BDNF. According to numerous research, high levels of BDNF are connected to a lower risk of developing a neurodegenerative disease. As a result, we want to concentrate on BDNF in this article and outline its protective role against neurological disorders.

Interleukin-17A knockout or self-recovery alleviated autoimmune reaction induced by fluoride in mouse testis.

Fluoride (F) is usually treated as a hazardous material, and F-caused public health problem has attracted global attention. Previous studies demonstrate that interleukin-17A (IL-17A) plays a crucial role in F-elicited autoimmune orchitis and self-recovery reverses F-induced testicular toxicity to some extent, but these basic mechanisms remain unclear. Thus, we established a 180 d F exposure model of wild type (WT) mice and IL-17A knockout mice (C57BL/6 J background), and 60 d & 120 d self-recovery model based on F exposure model of WT mice, and used various techniques like qRT-PCR, western blot, immunohistochemistry and ELISA to further explore the mechanism of F-induced autoimmune reaction, the role of IL-17A in it and the reversibility of F-caused toxicity in testis. The results indicated that F exposure for 180 d caused the decreased sperm quality, the damaged testis histopathology, the enhanced mRNA and protein expression levels of inflammatory cytokines, the changes of autoantibody such as the appearance and increased content of anti-testicular autoantibodies in sera and the autoantibody deposition in testis, the alterations of autoimmune related genes containing the decreased mRNA and protein expressions of AIRE and FOXP3 with an increase of MHCII, and the reduced protein expressions of CTLA4, and the activation of IL-17A signaling cascade like the elevated mRNA and protein expressions of IL-17A, Act1, NF-κB, AP-1 and CEBPß, and the increased protein expressions of IL-17RC, with a decrease of IκBα. After IL-17A knockout, 29 of 35 F-induced changes were alleviated. In two self-recovery models, all F-caused differences except fluorine concentration in femur were gradually restored in a time-dependent manner. This study concluded that IL-17A knockout or self-recovery attenuated F-induced testicular injury and decrease of sperm quality through alleviating autoimmune reaction which was involved with the activation of IL-17A pathway, the damage of self-tolerance and the enhancement of antigen presentation.

Distribution characteristics and regulation of amino acids and fatty acids in muscle and adipose tissues of sheep grown in natural grazing environment.

The composition of amino acid and fatty acid has a vital function on meat quality and animal health. However, the underlying mechanism of amino acid and fatty acid metabolism in sheep during different grazing periods is still unclear. In this study, a total of 12 sheep were employed in different grazing periods. Our results showed that the composition of amino acids and fatty acids in muscle and adipose tissues was significantly altered between dry grass (DG) period and green grass (GG) period. Changes in the activities of the metabolism-related enzymes including BCKD, BCAT2, ACC, SCD, HSL, GSK3ß, p-GSK3ß, and FABP4 were observed in muscle and adipose during different grazing periods. In addition, the mRNA expression levels of ACC, FAS, SCD, HSL, LPL, and DGAT1 in muscle and adipose tissue were changed markedly in different grazing periods. Furthermore, the expression levels of mTOR and ß-catenin/PPARγ/C/EBPα pathway-related proteins were predominantly altered in muscle and adipose among DG and GG. Taken together, all investigations simplified the process of amino acid and fatty acid metabolism disorders caused by different grazing periods, and the mTOR and ß-catenin/PPARγ/C/EBPα play the essential role in this process, which provided an underlying mechanism of metabolism and meat quality.

Fluoride exposure induces mitochondrial damage and mitophagy via activation of the IL-17A pathway in hepatocytes.

As an environmental toxicant, the damage of fluoride to the body has attracted global attention. Because liver is an essential organ for fluoride accumulation and damage. Our previous studies revealed fluoride-induced hepatic injury through interleukin 17A (IL-17A) pathway, but the underlying cellular mechanism remains unclear. Hence, this research explored the mechanism of IL-17A pathway and mitophagy in fluoride-induced liver injury through the use of the mice fluorosis model, IL-17A addition fluorosis cell model, IL-17A gene knockout mice fluorosis model, flow cytometry, immunohistochemistry, fluorescence double staining, ELISA, western blotting, and other techniques. The results showed that fluoride reduced the bodyweight and liver coefficient, increased the bone fluoride content, the aspartate aminotransferase (AST), alanine aminotransferase (ALT), glutamate dehydrogenase (GDH) levels, caspase 8 and caspase 9 activities, and induced liver morphology and ultrastructure damage. Furthermore, the protein expression levels of IL-17A pathway key proteins, IL-17A, IL-17R, and Act1 were increased, but IκB was decreased after fluoride exposure. In addition, fluoride exposure elevated the mitochondrial depolarization percent, the mitochondria damage, the fluorescent spots of mitophagy, and the LC3II/LC3I protein relative expression level. To further verify the role of the IL-17A pathway in fluoride-induced hepatocyte mitochondrial damage and mitophagy disorder, the IL-17A was added and knocked out in cells of animals. The results showed that the addition of IL-17A aggravated fluoride-induced liver morphology and functional damage, activation of the IL-17A pathway, mitochondrial injury, and mitophagy, but the IL-17A knockout mitigated fluoride-induced changes. These results suggested that fluoride exposure induced mitochondrial damage and mitophagy through the IL-17A pathway in hepatocytes.

Cellular and mitochondrial taurine depletion in bile duct ligated rats: a justification for taurine supplementation in cholestasis/cirrhosis.

Taurine (TAU) is a free amino acid abundant in the human body. Various physiological roles have been attributed to TAU. At the subcellular level, mitochondria are the primary targets for TAU function. Meanwhile, it has been found that TAU depletion is associated with severe pathologies. Cholestasis is a severe clinical complication that can progress to liver fibrosis, cirrhosis, and hepatic failure. Bile duct ligation (BDL) is a reliable model for assessing cholestasis/cirrhosis and related complications. The current study was designed to investigate the effects of cholestasis/cirrhosis on tissue and mitochondrial TAU reservoirs. Cholestatic rats were monitored (14 and 42 days after BDL surgery), and TAU levels were assessed in various tissues and isolated mitochondria. There was a significant decrease in TAU in the brain, heart, liver, kidney, skeletal muscle, intestine, lung, testis, and ovary of the BDL animals (14 and 42 days after surgery). Mitochondrial levels of TAU were also significantly depleted in BDL animals. Tissue and mitochondrial TAU levels in cirrhotic animals (42 days after the BDL operation) were substantially lower than those in the cholestatic rats (14 days after BDL surgery). These data indicate an essential role for tissue and mitochondrial TAU in preventing organ injury induced by cholestasis/cirrhosis and could justify TAU supplementation for therapeutic purposes.

Taurine mitigates the development of pulmonary inflammation, oxidative stress, and histopathological alterations in a rat model of bile duct ligation.

Lung injury is a significant complication associated with cholestasis/cirrhosis. This problem significantly increases the risk of cirrhosis-related morbidity and mortality. Hence, finding effective therapeutic options in this field has significant clinical value. Severe inflammation and oxidative stress are involved in the mechanism of cirrhosis-induced lung injury. Taurine (TAU) is an abundant amino acid with substantial anti-inflammatory and antioxidative properties. The current study was designed to evaluate the role of TAU in cholestasis-related lung injury. For this purpose, bile duct ligated (BDL) rats were treated with TAU (0.5 and 1% w: v in drinking water). Significant increases in the broncho-alveolar lavage fluid (BALF) level of inflammatory cells (lymphocytes, neutrophils, basophils, monocytes, and eosinophils), increased IgG, and TNF-α were detected in the BDL animals (14 and 28 days after the BDL surgery). Alveolar congestion, hemorrhage, and fibrosis were the dominant pulmonary histopathological changes in the BDL group. Significant increases in the pulmonary tissue biomarkers of oxidative stress, including reactive oxygen species formation, lipid peroxidation, increased oxidized glutathione levels, and decreased reduced glutathione, were also detected in the BDL rats. Moreover, significant myeloperoxidase activity and nitric oxide levels were seen in the lung of BDL rats. It was found that TAU significantly blunted inflammation, alleviated oxidative stress, and mitigated lung histopathological changes in BDL animals. These data suggest TAU as a potential protective agent against cholestasis/cirrhosis-related lung injury.

Arsenic-induced autophagy regulates apoptosis in AML-12 cells.

Arsenic (As), a potent toxicant, is known to be a hepatotoxicant. Although As induced liver apoptosis and autophagy, the relationship between apoptosis and autophagy of hepatocytes caused by As remains largely unknown. 3-methyladenine (3-MA) and rapamycin can inhibit and promote autophagy of AML-12 cells, respectively. Hence, in this study, AML-12 cells were treated with different concentrations (0, 2, 4, 6, 8, 10 and 12 µmol/L) of As2O3, and 5 mmol/L 3-MA or 100 nmol/L rapamycin were applied to distinguish the effect of autophagy on apoptosis in AML-12. Results showed that exposure to As induced cell apoptosis and autophagy, which were mediated by the significantly altered expression levels of autophagy markers (mTOR, LC3, PI3K and P62), and apoptosis markers (Bcl-2 and caspase-3). Further analysis indicated that a certain dosage of 3-MA and rapamycin decreased apoptosis and the caspase-3 expression, which suggested that As-induced autophagy regulated AML-12 cells apoptosis through the expressions of PI3K, mTOR, P62 and Bcl-2.

Mitochondrial dysfunction and oxidative stress are involved in the mechanism of tramadol-induced renal injury.

Tramadol (TMDL) is an opioid analgesic widely administered for the management of moderate to severe pain. On the other hand, TMDL is commonly abused in many countries because of its availability and cheap cost. Renal injury is related to high dose or chronic administration of TMDL. No precise mechanism for TMDL-induced renal damage has been identified so far. The current study aimed to evaluate the potential role of oxidative stress and mitochondrial impairment in the pathogenesis of TMDL-induced renal injury. For this purpose, rats were treated with TMDL (40 and 80 â€‹mg/kg, i.p, 28 consecutive days). A significant increase in serum Cr and BUN was detected in TMDL groups. On the other hand, TMDL (80 â€‹mg/kg) caused a substantial increase in urine glucose, ALP, protein, and γ-GT levels. Moreover, urine Cr was significantly decreased in TMDL-treated rats (40 and 80 â€‹mg/kg). Renal histopathological alterations included inflammation, necrosis, and tubular degeneration in the kidney of TMDL-treated animals. Reactive oxygen species (ROS) formation, increased oxidized glutathione (GSSG), lipid peroxidation, and protein carbonylation was increased, whereas total antioxidant capacity and reduced glutathione levels were considerably decreased in TMDL groups. Significant mitochondrial impairment was also detected in the form of mitochondrial depolarization, adenosine-tri-phosphate (ATP) depletion, mitochondrial permeabilization, lipid peroxidation, and decreased mitochondrial dehydrogenase activity in the kidney of TMDL (80 â€‹mg/kg)-treated animals. These data suggest mitochondrial impairment and oxidative stress as mechanisms involved in the pathogenesis of TMDL-induced renal injury.

Effects of Different Doses of Calcium on the Mitochondrial Apoptotic Pathway and Rho/ROCK Signaling Pathway in the Bone of Fluorosis Rats.

For this study, we investigate more deeply the effect calcium (Ca) develops on the mechanism underlying fluoride-triggered osteocyte apoptosis. We detected the morphology of osteocytes by HE staining, mitochondrial microstructure by using the transmission electron microscope, and the biochemical indexes related to bone metabolism and the expression of apoptosis-related genes. These results showed that NaF brought out the reduced osteocytes and ruptured mitochondrial outer membrane, with a significantly increased StrACP activity by 10.414 IU/L at the 4th week (P < 0.05), markedly upregulating the mRNA expression of Bax, Cyto-C, Apaf-1, caspase-7, ROCK-1, BMP-2, and BGP (P < 0.01), as well as caspase-6 (P < 0.05), while downregulating Bcl-2 by 61.3% (P < 0.01). Through immunohistochemical analysis, we also found that NaF notably increased the protein expression of ROCK-1 (P < 0.05) and Cyto-C, BMP-2, and BGP (P < 0.01), suggesting that NaF triggered the activation of the mitochondrial apoptotic pathway and Rho/ROCK signaling pathway. Nevertheless, 1% Ca supplementation in diet notably enhanced the mRNA expression of Bcl-2 by 39.3% (P < 0.01), thus blocking the increment of the expression of mitochondrial apoptotic pathway-related genes and ROCK-1. Meanwhile, Ca could attenuate the StrACP activity by 10.741 IU/L at the 4th week (P < 0.05) and protect the integrity of the mitochondrial outer membrane. These findings strongly suggest that 1% Ca abated the mitochondrial apoptosis pathway by increasing the anti-apoptotic gene Bcl-2 expression, and effectively inhibited the hyper-activation of ROCK-1, dually protecting the structural integrity of the mitochondrial outer membrane and maintaining normal cellular metabolic function.

The inhibition of NFкB signaling and inflammatory response as a strategy for blunting bile acid-induced hepatic and renal toxicity.

The cholestatic liver injury could occur in response to a variety of diseases or xenobiotics. Although cholestasis primarily affects liver function, it has been well-known that other organs such as the kidney could be influenced in cholestatic patients. Severe cholestasis could lead to tissue fibrosis and organ failure. Unfortunately, there is no specific therapeutic option against cholestasis-induced organ injury. Hence, finding the mechanism of organ injury during cholestasis could lead to therapeutic options against this complication. The accumulation of potentially cytotoxic compounds such as hydrophobic bile acids is the most suspected mechanism involved in the pathogenesis of cholestasis-induced organ injury. A plethora of evidence indicates a role for the inflammatory response in the pathogenesis of several human diseases. Here, the role of nuclear factor-kB (NFkB)-mediated inflammatory response is investigated in an animal model of cholestasis. Bile duct ligated (BDL) animals were treated with sulfasalazine (SSLZ, 10 and 100 mg/kg, i.p) as a potent inhibitor of NFkB signaling. The NFkB proteins family activity in the liver and kidney, serum and tissue levels of pro-inflammatory cytokines, tissue biomarkers of oxidative stress, serum markers of organ injury, and the liver and kidney histopathological alterations and fibrotic changes. The oxidative stress-mediated inflammatory-related indices were monitored in the kidney and liver at scheduled time intervals (3, 7, and 14 days after BDL operation). Significant increase in serum and urine markers of organ injury, besides changes in biomarkers of oxidative stress and tissue histopathology, were evident in the liver and kidney of BDL animals. The activity of NFkB proteins (p65, p50, p52, c-Rel, and RelB) was significantly increased in the liver and kidney of cholestatic animals. Serum and tissue levels of pro-inflammatory cytokines (IL-1ß, IL-2, IL-6, IL-7, IL-12, IL-17, IL-18, IL-23, TNF-α, and INF-γ) were also higher than sham-operated animals. Moreover, TGF- ß, α-SMA, and tissue fibrosis (Trichrome stain) were evident in cholestatic animals' liver and kidneys. It was found that SSLZ (10 and 100 mg/kg/day, i.p) alleviated cholestasis-induced hepatic and renal injury. The effect of SSLZ on NFkB signaling and suppression of pro-inflammatory cytokines could play a significant role in its protective role in cholestasis. Based on these data, NFkB signaling could receive special attention to develop therapeutic options to blunt cholestasis-induced organ injury.

The activation of nuclear factor-E2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling blunts cholestasis-induced liver and kidney injury.

Cholestasis is a severe clinical complication that severely damages the liver. Kidneys are also the most affected extrahepatic organs in cholestasis. The pivotal role of oxidative stress has been mentioned in the pathogenesis of cholestasis-induced organ injury. The activation of the nuclear factor-E2-related factor 2 (Nrf2) pathway is involved in response to oxidative stress. The current study was designed to evaluate the potential role of Nrf2 signaling activation in preventing bile acids-induced toxicity in the liver and kidney. Dimethyl fumarate was used as a robust activator of Nrf2 signaling. Rats underwent bile duct ligation surgery and were treated with dimethyl fumarate (10 and 40 mg/kg). Severe oxidative stress was evident in the liver and kidney of cholestatic animals (P < 0.05). On the other hand, the expression and activity of Nrf2 and downstream genes were time-dependently decreased (P < 0.05). Moreover, significant mitochondrial depolarization, decreased ATP levels, and mitochondrial permeabilization were detected in bile duct-ligated rats (P < 0.05). Histopathological alterations included liver necrosis, fibrosis, inflammation and kidney interstitial inflammation, and cast formation. It was found that dimethyl fumarate significantly decreased hepatic and renal injury in cholestatic animals (P < 0.05). Based on these data, the activation of the cellular antioxidant response could serve as an efficient therapeutic option for managing cholestasis-induced organ injury.

Pentoxifylline mitigates cholestasis-related cholemic nephropathy.

Aim of the study: Cholestasis is the stoppage of bile flow that primarily affects liver function. On the other hand, kidneys are also severely influenced during cholestasis. Cholestasis-induced kidney injury is known as cholemic nephropathy (CN). There is no precise pharmacological option in CN. Previous studies revealed that oxidative stress plays a crucial role in the pathogenesis of CN. On the other hand, the positive effects of pentoxifylline (PTX) against renal injury with different etiologies have been frequently reported. In the current study, the potential nephroprotective role of PTX in cholestasis-induced renal injury is investigated. Material and methods: Bile duct ligated (BDL) rats were treated with PTX (10, 50, and 100 mg/kg), and renal markers of oxidative stress, urine level of inflammatory cytokines, as well as renal histopathological alterations were monitored. Results: Significant changes in oxidative stress markers were detected in the BDL group. On the other hand, it was found that PTX (10, 50, and 100 mg/kg) significantly ameliorated cholestasis-induced oxidative stress in renal tissue. Renal histopathological changes, including interstitial inflammation, tubular atrophy, fibrosis, and cast formation, were detected in the BDL rats. Moreover, urine pro-inflammatory cytokines [interleukin (IL)-1, IL-9, IL-18, tumor necrosis factor α (TNF-α), and interferon γ (INF-γ)] were significantly increased in the cholestatic animals. PTX (10, 50, and 100 mg/kg, 14 days) significantly ameliorated renal histopathological alterations and urine levels of inflammatory cytokines. Conclusions: These data indicate a potential nephroprotective role for PTX in cholestasis. The effects of PTX on oxidative stress parameters and the inflammatory response could play a primary role in its renoprotective mechanisms.

The Effects of Fluoride on the Gap-Junctional Intercellular Communication of Rats' Osteoblast.

The gap junction protein plays an important role in the bone formation and alteration of these proteins leading to cause bone development. Aim to determine the effects of different concentration of fluoride on gap-junctional intercellular communication (GJIC) related genes and proteins in the rats' osteoblast cells. We treated the osteoblast cells with various concentrations (0, 0.01, 0.1, 0.5, and 1.0 mM) NaF for 24 and 72 h. We used the scrape loading and dye transfer technique to research the intracellular connectivity. Moreover, the mRNA expression levels of connexin 43 (Cx43), connexin45 (Cx45), collagen I, and osteocalcin (OCN) were analyzed by qRT-PCR, the protein expression levels of connexin43 (Cx43) were analyzed by western blotting and immunofluorescence. Our results suggested that the osteoblast proliferations were decreased in the 0.5 and 1 mM NaF groups, after 24 and 72 treatments. The scrape loading and dye transfer experiment showed that the GJIC were increased in the 0.01 mM NaF group and decreased in the 0.5 and 1 mM NaF groups. In addition, the mRNA expressions of Cx43, Cx45, and OCN, and the protein expressions of Cx43 were increased in the 0.01 mM NaF group and decreased in the 0.5 and 1 mM NaF groups. In summary, these results suggest that the low concentration NaF is good for the GJIC, but the high concentration NaF damages the GJIC.

Self-recovery study of the adverse effects of fluoride on small intestine: Involvement of pyroptosis induced inflammation.

Increasing investigations suggest that fluoride (F) exposure was associated with gastrointestinal diseases, but related literatures were still largely insufficient and the underlying mechanisms have not been fully elucidated. Moreover, previous study in our lab reported F toxicity has the reversible tendency, but it still needs to be further explored. To address this issue, we established a 90 days F exposure and 15 days & 30 days self-recovery mice model, including control and three F groups (25, 50 and 100 mg/L sodium fluoride (NaF)) in each period. The results revealed that after 90 days F exposure, histological structure and ultrastructure of small intestine were markedly disrupted; the value of villus height to crypt depth, and expressions of tight junctions related mRNA and proteins were significantly decreased; intestinal permeability, pro-inflammatory cytokines and pyroptosis related mRNA and proteins were notably increased in duodenum, jejunum and ileum. However, intriguingly, after 30 days recovery period, indices in F groups almost all have recovered towards normalcy. Collectively, this study demonstrated that F exposure could impair the structure and epithelial barrier function of small intestine, leading to the intestinal inflammation, and pyroptosis may contribute to this damage; Furthermore, F toxicity on small intestine is reversible, and could be restored when off the F exposure environment for a certain period of time. Additionally, among the three regions of small intestine, duodenum seems more vulnerable to F exposure than jejunum and ileum.