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Tacrolimus (TAC), also called FK506, is one of the classical immunosuppressants to prevent allograft rejection after liver transplantation. However, it has been proved to be associated with post-transplant hyperlipemia. The mechanism behind this is unknown, and it is urgent to explore preventive strategies for hyperlipemia after transplantation. Therefore, we established a hyperlipemia mouse model to investigate the mechanism, by injecting TAC intraperitoneally for eight weeks. After TAC treatment, the mice developed hyperlipemia (manifested as elevated triglyceride (TG) and low-density lipoprotein cholesterol (LDL-c), as well as decreased high-density lipoprotein cholesterol (HDL-c)). Accumulation of lipid droplets was observed in the liver. In addition to lipid accumulation, TAC induced inhibition of the autophagy-lysosome pathway (microtubule-associated protein 1 light chain 3β (LC3B) II/I and LC3B II/actin ratios, transcription factor EB (TFEB), protein 62 (P62), and lysosomal-associated membrane protein 1 (LAMP1)) and downregulation of fibroblast growth factor 21 (FGF21) in vivo. Overexpression of FGF21 may reverse TAC-induced TG accumulation. In this mouse model, the recombinant FGF21 protein ameliorated hepatic lipid accumulation and hyperlipemia through repair of the autophagy-lysosome pathway. We conclude that TAC downregulates FGF21 and thus exacerbates lipid accumulation by impairing the autophagy-lysosome pathway. Recombinant FGF21 protein treatment could therefore reverse TAC-caused lipid accumulation and hypertriglyceridemia by enhancing autophagy.
Subject(s)
Animals , Mice , Tacrolimus , Liver , Cholesterol, LDL , Autophagy , Disease Models, AnimalABSTRACT
MiT family translocation renal cell carcinoma mainly includes Xp11.2/TFE3 gene fusion-related renal cell carcinoma (TFE3 RCC)and t(6; 11)/TFEB gene fusion-related renal cell carcinoma(TFEB RCC), which is rare and there is no standard treatment plan yet, and the prognosis is still controversial. For localized lesions, surgery is the first choice for treatment, and systemic treatment such as targeted drugs and immune checkpoint inhibitors can be combined when there is metastasis. The application of gene testing provides the basis for personalized treatment. TFE3 RCC is highly invasive and has a poor prognosis, while TFEB RCC usually has a biological behavior of inertia and a better prognosis.
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Background Liver damage presented in endemic arsenic poisoning is usually serious. Studies have shown that oxidative stress, proteasome beta 5 subunit (PSMB5), regulatory transcription factor EB (TFEB), and lysosomes are associated with liver injury, but their specific links to arsenic-induced liver injury remain unclear. Objective Using a sodium arsenite (NaAsO2)-induced rat liver injury model established earlier by the research group, the expressions of PSMB5, TFEB, and lysosomal associated membrane protein 1 (LAMP1) in liver tissues were detected. Methods Twenty-four SPF Wistar rats were randomly divided into control group, and low, medium, and high dose groups, with 6 rats in each group, half male and half female. The exposure concentrations were 0, 25, 50, and 100 mg·L−1 NaAsO2 solutions for 24 weeks. At the end of the experiment, liver was dissected after rats were anesthetized. The levels of alkaline phosphatase (ALP), alanine aminotransferase (ALT), total bile acid (TBA), and catalase (CAT) in liver tissues were detected by chemical colorimetry, and the levels of lipid peroxide (LPO), 4-hydroxynonenal (4-HNE), LAMP1, and cathepsin D (CTSD) in liver tissues were detected by enzyme-linked immunosorbent assay (ELISA); the transcriptional expression levels of PSMB5 and TFEB in liver tissues were detected by real-time fluorescence quantitative PCR (RT-qPCR), and the protein expressions of PSMB5, TFEB, and phosphorylated TFEB (p-TFEB) in liver tissues were detected by immunohistochemistry. Results The results of chemical colorimetry and ELISA showed that compared with the control group, the liver homogenate levels of ALP, TBA, and LAMP1 of each arsenic-exposed group, the ALT and LPO in the medium and high concentration groups, the 4-HNE and CTSD in the high concentration group were increased, while the CAT activity of each arsenic-exposed group was decreased (P<0.05). The results of real-time fluorescence quantitative PCR showed that the transcription levels of PSMB5 and TFEB in the liver tissues of each arsenic-exposed group were decreased compared with those of the control group (P<0.05). The results of immunohistochemistry showed that compared with the control group, the expression of PSMB5 of each arsenic-exposed group were decreased, the expression of TFEB in the medium and high concentration groups was decreased, while the expression of p-TFEB of each arsenic-exposed group was increased (P<0.05). The expression of TFEB protein gradually decreased in the nucleus, while the expression of p-TFEB protein gradually increased in the cytoplasm, but no expression of p-TFEB was found in the nucleus. The results of Pearson correlation analysis showed that PSMB5 in liver tissues was positively correlated with CAT (r=0.818, P＜0.05), and negatively correlated with 4-HNE and p-TFEB (r=−0.582, r=−0.899; P＜0.05); TFEB was negatively correlated with CTSD and LAMP1 (r=−0.457, r=−0.564; P＜0.05); CTSD was positively correlated with ALT and ALP (r=0.529, r=0.485; P＜0.05). Conclusion Long-term exposure to NaAsO2 can induce oxidative stress, inhibit the expression of PSMB5 and TFEB, promote the accumulation of p-TFEB in the cytoplasm, decrease the nuclear entry of active TFEB, damage the lysosome, and cause liver damage.
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OBJECTIVE@#To investigate the protective effects of curcumin(CUR) and its mechanism on a rat model of neurotoxicity induced by manganese chloride (MnCl2), which mimics mangnism.@*METHODS@#Sixty male SD rats were randomly divided into 5 groups, with 12 rats in each group. Control group received 0.9% saline solution intraperitoneally (ip) plus double distilled water (dd) H2O intragastrically (ig), MnCl2 group received 15 mg/kg MnCl2(Mn2+ 6.48 mg/kg) intraperitoneally plus dd H2O intragastrically, CUR group received 0.9% saline solution intraperitoneally plus 300 mg/kg CUR intragastrically, MnCl2+ CUR1 group received 15 mg/kg MnCl2 intraperitoneally plus 100 mg/kg curcumin intragastrically, MnCl2+ CUR2 group received 15 mg/kg MnCl2 intraperitoneally plus 300 mg/kg CUR intragastrically, 5 days/week, 4 weeks. Open-field and rotarod tests were used to detect animals' exploratory behavior, anxiety, depression, movement and balance ability. Morris water maze (MWM) experiment was used to detect animals' learning and memory ability. ICP-MS was used to investigate the Mn contents in striata. The rats per group were perfused in situ, their brains striata were removed by brains model and fixed for transmission electron microscope (TEM), histopathological and immunohistochemistry (ICH) analyses. The other 6 rats per group were sacrificed. Their brains striata were removed and protein expression levels of transcription factor EB (TFEB), mammalian target of rapamycin (mTOR), p-mTOR, Beclin, P62, microtubule-associated protein light chain-3 (LC3) were detected by Western blotting. Terminal deoxynucleotidyl transterase-mediated dUTP nick end labeling (TUNEL) staining was used to determine neurocyte apoptosis of rat striatum.@*RESULTS@#After exposure to MnCl2 for four weeks, MnCl2-treated rats showed depressive-like behavior in open-field test, the impairments of movement coordination and balance in rotarod test and the diminishment of spatial learning and memory in MWM (P < 0.05). The striatal TH+ neurocyte significantly decreased, eosinophilic cells, aggregative α-Syn level and TUNEL-positive neurocyte significantly increased in the striatum of MnCl2 group compared with control group (P < 0.05). Chromatin condensation, mitochondria tumefaction and autophagosomes were observed in rat striatal neurocytes of MnCl2 group by TEM. TFEB nuclear translocation and autophagy occurred in the striatum of MnCl2 group. Further, the depressive behavior, movement and balance ability, spatial learning and memory ability of MnCl2+ CUR2 group were significantly improved compared with MnCl2 group (P < 0.05). TH+ neurocyte significantly increased, the eosinophilic cells, aggregative α-Syn level significantly decreased in the striatum of MnCl2+ CUR2 group compared with MnCl2 group. Further, compared with MnCl2 group, chromatin condensation, mitochondria tumefaction was alleviated and autophagosomes increased, TFEB-nuclear translocation, autophagy was enhanced and TUNEL-positive neurocyte reduced significantly in the striatum of MnCl2+ CUR2 group (P < 0.05).@*CONCLUSION@#Curcumin alleviated the MnCl2-induced neurotoxicity and α-Syn aggregation probably by promoting TFEB nuclear translocation and enhancing autophagy.
Subject(s)
Animals , Male , Rats , Autophagy , Chromatin , Curcumin/pharmacology , Mammals , Manganese/toxicity , Rats, Sprague-Dawley , Saline Solution/pharmacology , TOR Serine-Threonine KinasesABSTRACT
ObjectiveRecent studies revealed that the transcription factor EB (TFEB) plays an important role in regulating autophagy, reducing intracellular lipids, and inhibiting atherosclerosis. This study aims to explore the effects of atorvastatin (ATV) on autophagy and cholesterol levels of foam cells by activating TFEB.MethodsHuman mononuclear cell line THP-1 was cultured in vitro and induced to differentiate into macrophages using phorbol ester. Oxidized low-density lipoprotein (oxLDL) was added to macrophages, which were induced for 48 hours to establish a foam cell model. The experiment was divided into four groups: blank group, model group (oxLDL group), oxLDL+ Chloroquine (CQ) group, oxLDL+ ATV group, and oxLDL+CQ+ ATV group. Cells in each group were treated with drugs for 48 h. The toxicity of ATV and chloroquine on the cells was detected by the CCK8 method. Oil red O staining was used to test the level of lipid droplets. Oxidase method was used to detect levels of intracellular free cholesterol (FC), total cholesterol (TC) and others related to. Cholesterol efflux fluorescence analysis was used to determine the cholesterol efflux rate of the cells. Expression of I, P62, TFEB, LAMP 1 protein was determined by Western blot.ResultsThe results of the CCK8 method showed that the cell survival rate decreased significantly with the increase of ATV and CQ concentrations (P<0.01). Compared to the blank group, the levels of lipid droplets, FC, TC, and CE/TC in the model group significantly increased (P<0.05), and the cholesterol outflow rate significantly decreased (P<0.05). Compared to the model group, the intracellular lipid droplets, FC, TC, and CE/TC levels in the oxLDL+CQ group elevated significantly (P<0.05), while the cholesterol outflow rate decreased significantly (P<0.05). The intracellular lipid droplets, FC, TC, and CE/TC contents in the oxLDL+ATV group decreased significantly (P<0.05), and the cholesterol outflow rate increased significantly (P<0.05). Compared to the oxLDL+CQ group, the intracellular lipid droplets, FC, TC, and CE/TC content in the oxLDL+CQ+ATV group decreased significantly (P<0.05), while the cholesterol outflow rate increased significantly (P<0.05). Western blotting results showed that protein expression levels of LC3II/I, P62 and TFEB were decreased in the model histone in comparison to the blank group (P<0.05). Compared to the expression levels of LC3II/I, P62, TFEB and LAMP1 ((1.006±0.052), (0.183±0.013), (0.333±0.020), and (0.957±0.026)) in the model group, the expression levels of oxLDL+CQ histamine ((1.594±0.017), (0.257±0.006), (0.477±0.024), and (0.957±0.026)) were significantly higher (P<0.05).The protein expression levels of LC3II/I, TFEB and LAMP1 in oxLDL+ATV group ((1.146±0.060), (0.540±0.031), and (1.027±0.054)) were increased, while the protein expression levels of P62 (0.115±0.009) were decreased (P<0.05). Compared to LC3II/I and P62 in oxLDL+CQ group, the expression level of oxLDL+CQ+ATV histone was decreased ((1.419±0.036) and (0.165±0.006)), and the difference was statistically significant (P< 0.05).ConclusionATV can increase the cholesterol outflow rate of macrophages, reduce the level of cholesterol and lipid droplets in macrophages, and reduce the formation of foam cells. The mechanisms behind this are still unknown, which may be related to the activation of TFEB by ATV and influencing the process of autophagy.
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Background@#Acute lung injury (ALI) is characterized by an acute inflammatory process, and oxidative stress in the lung tissue leads to a lack of effective therapeutics. This study aimed to identify whether the overexpression of transcription factor EB (TFEB) regulates mitophagy to protect against lipopolysaccharide (LPS)-induced ALI.@*Methods@#We detected the expression of inflammatory factors, cytochrome c (Cyt.c) and nicotinamide adenine dinucleotide phosphate (NADPH), and autophagy-related proteins and observed the changes in lung histopathology induced by ALI in rats and the changes in the cell ultrastructure of primary alveolar type II epithelial cells induced by changing the expression of TFEB in the context of ALI.@*Results@#The overexpression of TFEB could reduce the expression of proinflammatory factors, such as IL-1 and IL-6, and increase the expression of anti-inflammatory factors, such as IL-10, both in vitro and in vivo. In addition, the overexpression of TFEB could reduce the Cyt.c and NADPH levels both in vivo and in vitro. The overexpression of TFEB could upregulate the expression of autophagy-related proteins, such as lysosomal-associated membrane protein 1 (LAMP1), microtubule-associated protein light chain 3B (LC3B), and Beclin both in vivo and in vitro, and promote mitochondrial autophagy. The overexpression of TFEB significantly improved the histopathologic changes induced by LPS-induced ALI in rats. However, low TFEB expression produced the opposite results.@*Conclusion@#TFEB overexpression can decrease inflammation and mitochondrial damage in the lung tissue and alveolar epithelial cells through regulating mitochondrial autophagy to protect against LPS-induced ALI. Therefore, TFEB is likely a potential therapeutic target in LPS-induced ALI.
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Transcription factor EB(TFEB)is a member of the MiTF/TFE family and plays an important role in cell stress,metabolism,cancer and so on.There are relatively few studies on the role of TFEB in renal diseases.TFEB was initially found to be highly expressed in TFEB-fusion renal cell carcinoma and plays a key role in the development of re-nal cell carcinoma.Blocking the downstream signaling pathway activated by TFEB would be a promising treatment for TFEB-fusion renal cell carcinoma.On the contrary,the expression of TFEB in renal intrinsic cells is decreased in diabetic kidney disease,leading to a blockage in the autophagy-lysosome pathway.TFEB enhances the ability of cell stress and self-repair,and then delays the progress of diabetic kidney disease.In cystine nephropathy,TFEB expression is reduced in re-nal tubular epithelial cells and compensatory activation is insufficient as well.TFEB over-expression effectively eliminates intracellular cystine and repairs damaged lysosome,which is expected to alleviate or cure the Fanconi syndrome.In summa-ry,TFEB plays a key role in different kidney diseases,and targeted regulation of TFEB provides new hope for the treatment of kidney diseases.
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Translocation renal cell carcinoma (RCC) is a family of rare tumors recently identified in the pediatric and young adult population. We report the first case of a young woman from French West Indies with sickle cell anemia who developed a translocation RCC t(6;11)(p21;q12). Usually people with the sickle cell condition are known to develop renal medullary carcinoma (RMC). To our knowledge, this is the first case described in the literature of a translocation RCC associated with sickle cell disease. Here we discuss the relation between translocation RCC, RMC, and sickle cell disease.