Characterization and expression analysis of seven lipid metabolism-related genes in yellow catfish Pelteobagrus fulvidraco fed high fat and bile acid diet.

SREBPs, such as SREBP1 and SREBP2, were the key transcriptional factors regulating lipid metabolism. The processing of SREBPs involved many genes, such as scap, s1p, s2p, cideb. Here, we deciphered the full-length cDNA sequences of scap, srebp1, srebp2, s1p, s2p, cideb and cidec from yellow catfish Pelteobagrus fulvidraco. Their full-length cDNA sequences ranged from 1587 to 3884 bp, and their ORF length from 1191 to 2979 bp, encoding 396-992 amino acids. Some conservative domains were predicted, including the multiple transmembrane domains in SCAP, the bHLH-ZIP domain in SREBP1 and SREBP2, the ApoB binding region, ER targeting region and LD targeting region in CIDEb, the LD targeting region in the CIDEc, the conserved catalytic site and processing site in S1P, and the transmembrane helix domain in S2P. Their mRNA expression could be observed in the heart, spleen, liver, kidney, brain, muscle, intestine and adipose, but varied with tissues. The changes of their mRNA expression in responses to high-fat (HFD) and bile acid (BA) diets were also investigated in the brain, heart, intestine, kidney and spleen tissues. In the brain, HFD significantly increased the mRNA expression of seven genes (scap, srebp1, srebp2, s1p, s2p, cideb and cidec), and the BA attenuated the increase of scap, srebp1, srebp2, s1p, s2p, cideb and cidec mRNA expression induced by HFD. In the heart, HFD significantly increased the mRNA abundances of six genes (srebp1, srebp2, scap, s2p, cideb and cidec), and BA attenuated the increase of their mRNA abundances induced by HFD. In the intestine, HFD increased the cideb, s1p and s2p mRNA abundances, and BA attenuated the HFD-induced increment of their mRNA abundances. In the kidney, HFD significantly increased the scap, cidec and s1p mRNA expression, and BA diet attenuated the increment of their mRNA expression. In the spleen, HFD treatment increased the scap, srebp2, s1p and s2p mRNA expression, and BA diet attenuated HFD-induced increment of their mRNA expression. Taken together, our study elucidated the characterization, expression profiles and transcriptional response of seven lipid metabolic genes, which would serve as the good basis for the further exploration into their function and regulatory mechanism in fish.

Novel mechanism for zinc inducing hepatic lipolysis via the HDAC3-mediated deacetylation of ß-catenin at lysine 311.

Zinc (Zn) is a multipurpose trace element indispensable for vertebrates and possesses essential regulatory roles in lipid metabolism, but the fundamental mechanism remains largely unknown. In the current study, we found that a high-Zn diet significantly increased hepatic Zn content and influenced the expression of Zn transport-relevant genes. Dietary Zn addition facilitated lipolysis, inhibited lipogenesis, and controlled ß-catenin signal; Zn also promoted T-cell factor 7-like 2 (TCF7L2) to interact with ß-catenin and regulating its transcriptional activity, thereby inducing lipolysis and inhibiting lipogenesis; Zn-induced lipid degradation was mediated by histone deacetylase 3 (HDAC3) which was responsible for ß-catenin deacetylation and the regulation of ß-catenin signal under the Zn treatment. Mechanistically, Zn promoted lipid degradation via stimulating HDAC3-mediated deacetylation of ß-catenin at lysine 311 (K311), which enhanced the interaction between ß-catenin and TCF7L2 and then transcriptionally inhibited fatty acid synthase (FAS), 2-acylglycerol O-acyltransferase 2 (MOGAT2), and sterol regulatory element-binding protein 1 (SREBP1) expression, but elevated the mRNA abundance of adipose triglyceride lipase (ATGL), hormone-sensitive lipase a (HSLA) and carnitine palmitoyltransferase 1a1b (CPT1A1B). Overall, our research reveals a novel mechanism into the important roles of HDAC3/ß-catenin pathway in Zn promoting lipolysis and inhibiting lipogenesis, and highlights the essential roles of K311 deacetylation in ß-catenin actions and lipolytic metabolism, and accordingly provides novel insight into the prevention and treatment of steatosis in the vertebrates.

Glycophagy mediated glucose-induced changes of hepatic glycogen metabolism via OGT1-AKT1-FOXO1Ser238 pathway.

Glycophagy is the autophagy degradation of glycogen. However, the regulatory mechanisms for glycophagy and glucose metabolism remain unexplored. Herein, we demonstrated that high-carbohydrate diet (HCD) and high glucose (HG) incubation induced glycogen accumulation, protein kinase B (AKT)1 expression and AKT1-dependent phosphorylation of forkhead transcription factor O1 (FOXO1) at Ser238 in the liver tissues and hepatocytes. The glucose-induced FOXO1 phosphorylation at Ser238 prevents FOXO1 entry into the nucleus and the recruitment to the GABA(A) receptor-associated protein like 1 (gabarapl1) promoter, reduces the gabarapl1 promoter activity, and inhibits glycophagy and glucose production. The glucose-dependent O-GlcNAcylation of AKT1 by O-GlcNAc transferase (OGT1) enhances the stability of AKT1 protein and promotes its binding with FOXO1. Moreover, the glycosylation of AKT1 is crucial for promoting FOXO1 nuclear translocation and inhibiting glycophagy. Our studies elucidate a novel mechanism for glycophagy inhibition by high carbohydrate and glucose via OGT1-AKT1-FOXO1Ser238 pathway in the liver tissues and hepatocytes, which provides critical insights into potential intervention strategies for glycogen storage disorders in vertebrates, as well as human beings.

Differential distribution and prognostic value of CD4+ T cell subsets before and after radioactive iodine therapy in differentiated thyroid cancer with varied curative outcomes.

Differentiated thyroid cancer is the most frequently diagnosed endocrine tumor. While differentiated thyroid cancers often respond to initial treatment, little is known about the differences in circulating immune cells amongst patients who respond differently. A prospective study of 39 patients with differentiated thyroid cancer was conducted. Serum thyroglobulin levels and thyroid and immunological functions were tested before and after radioactive iodine treatment (RAIT). Efficacy assessments were performed 6 to 12 months after radioactive iodine treatment. Most patients showed an excellent response to radioactive iodine treatment. Before radioactive iodine treatment, the excellent response group had considerably fewer circulating CD4+ T cell subsets than the non-excellent response group. Both the excellent response and non-excellent response groups had considerably lower circulating CD4+ T lymphocyte subsets 30 days after radioactive iodine treatment, but those of the excellent response group were still lower than those of the non-excellent response group. All circulating CD4+ T cell subsets in the excellent response group rose by varying degrees by the 90th day, but only Treg cell amounts increased in the non-excellent response group. Interestingly, in the non-excellent response group, we noticed a steady drop in Th1 cells. However, the bulk of circulating CD4+ T cell subsets between the two groups did not differ appreciably by the 90th day. Finally, we discovered that CD4+ T cell subsets had strong predictive potential, and we thus developed high-predictive-performance models that deliver more dependable prognostic information. In conclusion, in individuals with differentiated thyroid cancer, there is great variation in circulating immune cells, resulting in distinct treatment outcomes. Low absolute CD4+ T cell counts is linked to improved clinical outcomes as well as stronger adaptive and resilience capacities.

Dynamic Immune Function Changes Before and After the First Radioactive Iodine Therapy After Total Resection of Differentiated Thyroid Carcinoma.

The effects of total thyroidectomy or radioactive iodine therapy on immune activation and suppression of the tumor microenvironment remain unknown. We aimed to investigate the effects of these treatments on the immune function in patients with differentiated thyroid carcinoma (DTC). Our cohort included 45 patients with DTC treated with total thyroidectomy and radioactive iodine therapy (RAIT). Immune function tests were performed by flow cytometry at 0, 30, and 90 days post-RAIT. Both the percentage and absolute number of circulating regulatory T cells were significantly lower in the postoperative DTC compared to the healthy controls. Notably, the absolute number of multiple lymphocyte subgroups significantly decreased at 30 days post-RAIT compared to those pre-RAIT. The absolute counts of these lymphocytes were recovered at 90 days post-RAIT, but not at pre-RAIT levels. Additionally, the Th17 cell percentage before RAIT was positively correlated with thyroglobulin (Tg) levels after RAIT. The tumor burden might contribute to increased levels of circulating Tregs. In conclusion, RAIT caused transient radiation damage in patients with DTC and the percentage of Th17 cells before RAIT could be a significant predictor of poor prognosis in patients with DTC.

Application of Tivantinib for Hepatocellular Carcinoma: A Meta-Analysis Study.

Objectives: The efficacy of tivantinib may have some potential in treating MET-high hepatocellular carcinoma, and we aim to compare tivantinib with placebo for the treatment of MET-high hepatocellular carcinoma. Methods: Several databases including PubMed, Cochrane Library, Web of Science, EBSCO, and EMbase have been systematically searched through March 2022, and we included studies regarding the treatment of MET-high hepatocellular carcinoma by using tivantinib versus placebo. Results: We finally include three RCTs. In comparison with placebo for MET-high hepatocellular carcinoma, tivantinib reveals no significant influence on overall survival (P=0.21), progression-free survival (P=0.13), time to progression (P=0.38), or grade ≥3 anemia (P=0.50) but increases the incidence of grade ≥3 neutropenia (P=0.04). Conclusions: Tivantinib may provide no additional benefits for MET-high hepatocellular carcinoma.

A pilot study: Gut microbiota, metabolism and inflammation in hypertensive intracerebral haemorrhage.

AIMS: In recent years, the incidence rate of hypertensive intracerebral haemorrhage (HICH) has been increasing, accompanied by high mortality and morbidity, which has brought a heavy burden to the social economy. However, the pathogenesis of HICH is still unclear. This study intends to explore the mechanism of gut microbiota metabolism and inflammation in the process of HICH to provide a theoretical basis for the diagnosis and treatment of HICH. METHODS AND RESULTS: HE staining showed that the brain tissues of model group had obvious oedema injury, which indicated that the HICH model was successfully constructed. ELISA analysis showed that IL-1ß and TNF-α levels in blood and brain tissues were significantly increased, and IL-10 level was significantly decreased in blood. IHC analysis showed that microglia and macrophages were activated in the model group. 16S rRNA sequence showed that the diversity of gut microbiota in HICH patients decreased. Also, the microbiota belonging to Firmicutes, Proteobacteria and Verrucomicrobia changed significantly. LC-MS/MS analysis showed that the metabolic phenotype of HICH patients changed. Also, the 3,7-dimethyluric acid- and 7-methylxanthine-related metabolic pathways of caffeine metabolism pathways were downregulated in patients with HICH. Bacteroides was negatively correlated with the IL-1ß and TNF-α levels. Blautia was negatively correlated with the IL-1ß and TNF-α levels, and positively correlated with the IL-10 level. Akkermansia was negatively correlated with the 3,7-dimethyluric acid and 7-methylxanthine. CONCLUSION: Our study suggested that HICH was accompanied by the increased inflammation marker levels in peripheral blood and brain, decreased gut microbiota diversity, altered gut metabolic phenotype and downregulation of caffeine metabolism pathway. SIGNIFICANCE AND IMPACT OF THE STUDY: Our study reported that HICH accompanied by the increased inflammation, decreased gut microbiota diversity and altered gut metabolic phenotype. Due to the number of patients, this work was a pilot study.

Absolute reduction in peripheral regulatory T cells in patients with Graves' disease and post-treatment recovery.

OBJECTIVE: Graves' disease (GD) is one of the most common autoimmune conditions, but the mechanisms underlying the associated induction of autoimmunity are not known. We explored the role of peripheral lymphocyte subpopulations in disease pathogenesis. METHODS: In total, 32 patients and 40 age- and sex-matched healthy controls were recruited in this study. Peripheral levels of T, B, NK, CD4+ T, CD8+ T, Th1, Th2, Th17, and Treg cells were measured using flow cytometry. For all patients, we compared all lymphocyte subpopulations between GD patients and healthy controls. Changes in patient lymphocyte subsets were compared before and after treatment. RESULTS: The absolute numbers of circulating Th17 cells (0.45 ± 1.16, p > 0.05) between GD patients and healthy controls were not significantly different. However, the percentage of Th17 cells was significantly increased (0.25 ± 0.11, p < 0.05). The absolute numbers and percentages of circulating Tregs in GD patients were significantly decreased compared with those in healthy participants (11.61 ± 2.75, p < 0.05). There was a significant difference in Treg absolute numbers between the untreated and drug-treated groups. Furthermore, we found that the Treg percentage in untreated patients (mean=4.78) was not significantly different from that in the drug-treated group (mean=4.81). In addition, circulating Treg absolute numbers in GD patients with exophthalmos were significantly lower than those in GD patients without exophthalmos (9.96 ± 4.16, p < 0.05). A similar trend was observed in GD patients with weight loss (11.97 ± 3.28, p < 0.05). CONCLUSION: GD pathogenesis was associated with a lower Treg population and an increased Th17/Treg ratio (T helper cell 17/ regulatory T cells). Th17 cells in this study were not related to the disease. Furthermore, anti-thyroid drug therapy improved immune-mediated system disorders. Finally, we found lower absolute numbers of circulating Tregs in GD patients with certain positive signs, such as exophthalmos and/or weight loss. Thus, immune changes are correlated with partial clinical manifestations.

4,5-Dimethoxycanthin-6-one is a novel LSD1 inhibitor that inhibits proliferation of glioblastoma cells and induces apoptosis and pyroptosis.

BACKGROUND: Glioblastoma is one of the most common fatal intracranial malignancies. Lysine-specific demethylase 1 (LSD1) reportedly has therapeutic effects on a variety of tumors. This study explored the therapeutic effect of LSD1 inhibition on glioblastoma cell lines and the possible underlying mechanisms. METHODS: The MTT assay was utilized to screen for the sensitivity of U87, U251 and T98G cells to 4, 5-dimethoxycarrageenin-6-one. qRT-PCR and western blot were used to measure the proliferation, apoptosis, and pyroptosis signaling pathway expression to observe the effect of LSD1 inhibition on U251 and T98G cells. Flow cytometry, immunofluorescence, immunohistochemistry, wound scratch, clone formation, and TUNEL assay were used to analyze the effects of 4, 5-dimethoxycanthin-6-one on glioblastoma cells. The effect of 4, 5-dimethoxycanthin-6-one was examined in vivo in BALB/c nude mice injected with U251 cells. HE staining was used to detect the histopathology of the tumor. RESULTS: LSD1 specifically catalyzes the demethylation of monomethylated and demethylated histone H3 lysine at position 4 (h3k4me1, h3k4me2, h3k4me3) and lysine at position 9 (h3k9me1). This regulated the transcriptional activity of proliferation, apoptosis, and pyroptosis signaling pathway genes. In vitro, the proliferation of glioblastoma cells was decreased in the 4, 5-dimethoxycanthin-6-one group. The expression of Caspase1 in glioblastoma cells treated with 4, 5-dimethoxycanthin-6-one increased, and the number of apoptotic cells increased. The tumor volume of mice injected with 4, 5-dimethoxycanthin-6-one decreased significantly. CONCLUSION: 4, 5-Dimethoxycanthin-6-one could act as a novel inhibitor of LSD1 to regulate glioblastoma, which could inhibit the proliferation of U251 and T98G cells and induce their apoptosis and pyroptosis. It is a potential drug for the treatment of glioblastoma.

Lipophagy mediated glucose-induced changes of lipid deposition and metabolism via ROS dependent AKT-Beclin1 activation.

High dietary carbohydrate intake leads to lipid accumulation in the intestinal tract, but the molecular mechanism remains unknown. In the present study, using yellow catfish (Pelteobagrus fulvidraco) as a model, we found that (1) high carbohydrate diets (HCD) and high glucose (HG) increased lipid deposition, up-regulated lipogenesis and fatty acid ß-oxidation, activated autophagy and induced oxidative stress in the intestinal tissues and intestinal epithelial cells (IECs); (2) lipophagy alleviated HG-induced lipid accumulation via the up-regulation of fatty acid ß-oxidation; (3) Akt interacted directly with Beclin1; (4) HG suppressed Akt1 phosphorylation, downregulated Akt1-mediated phosphorylation of Beclin1, activated lipophagy and alleviated the increment of TG deposition induced by HG with S87 and S292 being the key phosphorylation residues of Beclin1 in response to HG; (5) ROS generation mediated HG-induced activation of lipophagy and HG-induced suppression of AKT phosphorylation, activated AMPK and alleviated HG-induced increase of TG deposition. Our study provides mechanistic evidence that high carbohydrate- and glucose-induced lipophagy in intestine and IECs is associated with ROS-AKT-Beclin1-dependent activation of autophagy, which alleviates glucose-induced lipid accumulation. Our findings are important since the regulation of autophagy can be used as potential molecular targets for the prevention and treatment of lipotoxicity in the intestine of vertebrates, including humans.

Methionine-chelated Zn promotes anabolism by integrating mTOR signal and autophagy pathway in juvenile yellow catfish.

BACKGROUND: Amino acid-chelated zinc (Zn) can increase anabolism of animals. However, the underlying mechanisms are unclear. We aimed to examine how autophagy impact anabolism following a diet containing methionine-chelated Zn (ZnMet) compared with inorganic Zn (ZnSO4). METHODS: Yellow catfish (weight: 4.02 ± 0.08 g) were fed two diets containing ZnSO4 or ZnMet for 8 wk. The differences in transcriptional responses and corresponding biological profiles were compared between the livers of fish fed the two Zn sources of diets. Hepatocytes of yellow catfish were incubated for 48 h in medium containing ZnSO4 (10 µM ZnSO4) or ZnMet (10 µM ZnMet) after 2 h pretreated with or without pathway inhibitors. Intracellular Zn, TG and protein contents, lipid droplet and autophagic vesicles were detected. Ultrastructural observation, enzymatic activities, qPCR assays, western blot and immunofluorescence analysis were conducted. RESULTS: ZnMet up-regulated the expression of genes associated with anabolism and autophagy. The differentially expressed genes (DEG) analysis indicated that both mTOR and autophagy pathways were activated. ZnMet-induced activation of autophagy was mTOR-independent. In this process, forkhead box class O was deacetylated and activated, and induced autophagy, which provided substrates for energy generation. CONCLUSIONS: ZnMet increased anabolism through integrating mTOR signal and autophagy pathway in yellow catfish. The present study unravels a novel mechanism for amino acid-chelated minerals improving anabolism.

Clinical significance of the serum IgM and IgG to SARS-CoV-2 in coronavirus disease-2019.

OBJECTIVE: To explore the clinical value of serum IgM and IgG to SARS-CoV-2 in COVID-19. METHODS: 105 COVID-19 patients were enrolled as the disease group. 197 non-COVID-19 patients served as the control group. Magnetic chemiluminescent immunoassay (MCLIA) was used to detect the IgM and IgG. RESULTS: The peak of positive rates of SARS-CoV-2 IgM was about 1 week earlier than that of IgG. It reached to peak within 15-21 days and then began a slowly decline. The positive rates of IgG were increased with the disease course and reached the peak between 22 and 39 days. The differences in sensitivity of the three detection modes (IgM, IgG, and IgM + IgG) were statistically significant. The largest group of test cases (illness onset 15-21 days) showed that the positive rate of IgG was higher than IgM. Also, the sensitivity of IgM combined with IgG was higher than IgM or IgG. IgM and IgG were monitored dynamically for 16 patients with COVID-19, the results showed that serological transformation of IgM was carried out simultaneously with IgG in seven patients, which was earlier than IgG in four patients and later than IgG in five patients. CONCLUSION: The detection of SARS-CoV-2 IgM and IgG is very important to determine the course of COVID-19. Nucleic acid detection combined with serum antibody of SARS-CoV-2 may be the best laboratory indicator for the diagnosis of SARS-CoV-2 infection and the phrase and predication for prognosis of COVID-19.

Waterborne copper exposure up-regulated lipid deposition through the methylation of GRP78 and PGC1α of grass carp Ctenopharyngodon idella.

Early molecular events after the exposure of heavy metals, such as aberrant DNA methylation, suggest that DNA methylation was important in regulating physiological processes for animals and accordingly could be used as environmental biomarkers. In the present study, we found that copper (Cu) exposure increased lipid content and induced the DNA hypermethylation at the whole genome level. Especially, Cu induced hypermethylation of glucose-regulated protein 78 (grp78) and peroxisome proliferator-activated receptor gamma coactivator-1α (pgc1α). CCAAT/enhancer binding protein α (C/EBPα) could bind to the methylated sequence of grp78, whereas C/EBPß could not bind to the methylated sequence of grp78. These synergistically influenced grp78 expression and increased lipogenesis. In contrast, DNA methylation of PGC1α blocked the specific protein 1 (SP1) binding and interfered mitochondrial function. Moreover, Cu increased reactive oxygen species (ROS) production, activated endoplasmic reticulum (ER) stress and damaged mitochondrial function, and accordingly increased lipid deposition. Notably, we found a new toxicological mechanism for Cu-induced lipid deposition at DNA methylation level. The measurement of DNA methylation facilitated the use of these epigenetic biomarkers for the evaluation of environmental risk.

Effects of dietary carbohydrate sources on lipid metabolism and SUMOylation modification in the liver tissues of yellow catfish.

Dysregulation in hepatic lipid synthesis by excess dietary carbohydrate intake is often relevant with the occurrence of fatty liver; therefore, the thorough understanding of the regulation of lipid deposition and metabolism seems crucial to search for potential regulatory targets. In the present study, we examined TAG accumulation, lipid metabolism-related gene expression, the enzyme activities of lipogenesis-related enzymes, the protein levels of transcription factors or genes involving lipogenesis in the livers of yellow catfish fed five dietary carbohydrate sources, such as glucose, maize starch, sucrose, potato starch and dextrin, respectively. Generally speaking, compared with other carbohydrate sources, dietary glucose promoted TAG accumulation, up-regulated lipogenic enzyme activities and gene expressions, and down-regulated mRNA expression of genes involved in lipolysis and small ubiquitin-related modifier (SUMO) modification pathways. Further studies found that sterol regulatory element binding protein 1 (SREBP1), a key transcriptional factor relevant to lipogenic regulation, was modified by SUMO1. Mutational analyses found two important sites for SUMOylation modification (K254R and K264R) in SREBP1. Mutant SREBP lacking lysine 264 up-regulated the transactivation capacity on an SREBP-responsive promoter. Glucose reduced the SUMOylation level of SREBP1 and promoted the protein expression of SREBP1 and its target gene stearoyl-CoA desaturase 1 (SCD1), indicating that SUMOylation of SREBP1 mediated glucose-induced hepatic lipid metabolism. Our study elucidated the molecular mechanism of dietary glucose increasing hepatic lipid deposition and found that the SREBP-dependent transactivation was regulated by SUMO1 modification, which served as a new target for the transcriptional programmes governing lipid metabolism.

[Value of Serum Light Chain in Diagnosis and Evaluation of Efficacy for Multiple Myeloma].

OBJECTIVE: To explore the clinical application value of serum light chain (sLC) in the diagnosis and therapeutic efficacy evaluation for multiple myeloma. METHODS: 46 patients with newly diagnosed multiple myeloma were selected as MM group and 50 healthy persons as control group. Rate scattering immunoturbidimetry was used to detect serum light chain and immunoglobulin (Ig) in two groups, serum protein electrophoresis was used to detect M protein by agarose gel. Then, the sensitivity and specificity of the two methods in MM diagnosis were analyzed and compared, and the significance of sLC detection in MM diagnosis were discussed. In addition, 15 MM patients after received conventional therapy were tracked, sLC levels in five different therapentic times were recorded, and the effect of sLC in efficacy evaluation of MM was analyzed. RESULTS: There were 11 cases of IgA type, 15 cases of IgG type, 8 cases of light chain κ type, 8 cases of light chain λ type, 2 cases of IgD type, and 2 cases of non-secretion type. The sLC-κ, sLC-λ and their ratio (including light chain type and double clone type), IgA and IgG (except IgD type), as well as albumin, beta-globulin and gamma-globulin levels showed statistically significant differences (P＜0.05) compared with the control group. The sensitivity of serum protein electrophoresis, Ig quantification, sLC and its ratio in the diagnosis of multiple myeloma were 57%, 76% and 65%, and their specificity were 83%, 61% and 90%, respectively. After the second or third chemotherapy, the sLC-κ/λ ratio gradually approached the normal range as the disease reliefes, and the sLC-κ/λ ratio continued to be on or off the line at outliers or further away from the reference value as the disease progresses in MM patients with κ type or λ type. CONCLUSION: sLC detection shows positive significance in early diagnosis of multiple myeloma, SLC monitoring can be used for the efficacy evaluation for treatment of MM patients.

Waterborne Cu exposure increased lipid deposition and lipogenesis by affecting Wnt/ß-catenin pathway and the ß-catenin acetylation levels of grass carp Ctenopharyngodon idella.

Lipid metabolism could be used as a biomarker for environmental monitoring of metal pollution, including Cu. Given the potential role of the Wnt/ß-catenin signaling pathway and acetylation in lipid metabolism, the aim of this study was to investigate the mechanism of Wnt signaling and acetylation mediating Cu-induced lipogenesis. Grass carp Ctenopharyngodon idella, widely distributed freshwater teleost, were used as the model. We found that waterborne Cu exposure increased the accumulation of Cu and lipid, up-regulated lipogenesis, suppressed Wnt signaling, reduced ß-catenin protein level and its nuclear location, reduced the sirt1 mRNA levels and up-regulated the ß-catenin acetylation level. Further investigation found that Cu up-regulated lipogenesis through Wnt/ß-catenin pathway; Cu regulated the ß-catenin acetylation, and K311 was the key acetylated residue after Cu incubation. SIRT1 mediated Cu-induced changes of acetylated ß-catenin and played an essential role in nuclear accumulation of ß-catenin and Cu-induced lipogenesis. Cu facilitated lipid accumulation via the regulation of Wnt pathway by SIRT1. For the first time, our study uncovered the novel mechanism for Wnt/ß-catenin pathway and ß-catenin acetylation levels mediating Cu-induced lipid deposition, which provided insights into the association between Cu exposure and lipid metabolism in fish and had important environmental implications for monitoring metal pollution in the water by using new biomarkers involved in lipid metabolism.

Effects of Fat and Fatty Acids on the Formation of Autolysosomes in the Livers from Yellow Catfish Pelteobagrus Fulvidraco.

The autophagy-lysosome pathway, which involves many crucial genes and proteins, plays crucial roles in the maintenance of intracellular homeostasis by the degradation of damaged components. At present, some of these genes and proteins have been identified but their specific functions are largely unknown. This study was performed to clone and characterize the full-length cDNA sequences of nine key autolysosome-related genes (vps11, vps16, vps18, vps33b, vps41, lamp1, mcoln1, ctsd1 and tfeb) from yellow catfish Pelteobagrus fulvidraco. The expression of these genes and the transcriptional responses to a high-fat diet and fatty acids (FAs) (palmitic acid (PA) and oleic acid (OA)) were investigated. The mRNAs of these genes could be detected in heart, liver, muscle, spleen, brain, mesenteric adipose tissue, intestine, kidney and ovary, but varied with the tissues. In the liver, the mRNA levels of the nine autolysosome-related genes were lower in fish fed a high-fat diet than those fed the control, indicating that a high-fat diet inhibited formation of autolysosomes. Palmitic acid (a saturated FA) significantly inhibited the formation of autolysosomes at 12 h, 24 h and 48 h incubation. In contrast, oleic acid (an unsaturated FA) significantly induced the formation of autolysosomes at 12 h, but inhibited them at 24 h. At 48 h, the effects of OA incubation on autolysosomes were OA concentration-dependent in primary hepatocytes of P. fulvidraco. The results of flow cytometry and laser confocal observations confirmed these results. PA and OA incubation also increased intracellular non-esterified fatty acid (NEFA) concentration at 12 h, 24 h and 48 h, and influenced mRNA levels of fatty acid binding protein (fabp) and fatty acid transport protein 4 (fatp4) which facilitate FA transport in primary hepatocytes of P. fulvidraco. The present study demonstrated the molecular characterization of the nine autolysosome-related genes and their transcriptional responses to fat and FAs in fish, which provides the basis for further exploring their regulatory mechanism in vertebrates.

LncRNA SNHG12 inhibits miR-199a to upregulate SIRT1 to attenuate cerebral ischemia/reperfusion injury through activating AMPK signaling pathway.

Cerebral ischemia caused severe disability, and associated with a series of neurological events. Long non-coding RNA SNHG12 was found to be upregulated in mouse brain microvascular endothelial cells by cerebral ischemia. Moreover, it was reported that SNHG12 could directly interact with miR-199a and sirtuin 1 (SIRT1) as a direct target of miR-199a in other diseases. However, the function and mechanism of SNHG12 in cerebral ischemia and reperfusion (I/R) injury of neuronal cells remains unclear. The present study was thus designed to explore the potential effect of SNHG12 and to investigate the underlying mechanism in I/R neuronal cells. we found that SNHG12 was upregulated in primary neuronal cells and N2a cells and peaked at 12 h and 24 h after OGD/R treatment, respectively. Meanwhile, MTT assay showed that knockdown SNHG12 inhibited cell proliferation under OGD/R condition. And flow cytometry analyses revealed more apoptosis rate was caused by SNHG12 knockdown. Mechanistically, SNHG12 interacted with miR-199a and decreased the expression of miR-199a. Overexpression miR-199a largely inhibited the cell proliferation and induced the cell apoptosis. Meanwhile, SNHG12 was proven to target miR-199a and then activated SIRT1 expression, which finally led to activation of AMPK signaling pathway. In summary, we demonstrate SNHG12 targets miR-199a to upregulate SIRT1 expression, which attenuates cerebral ischemia/reperfusion injury through AMPK pathway activation. Our findings provide molecular mechanism by which SNHG12 attenuates cerebral I/R injury and facilitate development of therapeautical strategies for treating ischemia-induced stroke.

Molecular characterization of nine suppressors of cytokine signaling (SOCS) genes from yellow catfish Pelteobagrus fulvidraco and their changes in mRNA expression to dietary carbohydrate levels.

Suppressors of cytokine signaling (SOCS) are important molecules that mediates the regulation of glucose homeostasis. Here, we cloned and characterized the full-length cDNA sequences of nine genes of the SOCS family (SOCS1, 2, 3, 3b, 5, 5b, 6, 7 and CISH) from yellow catfish P. fulvidraco, explored their mRNA abundance across the tissues and their mRNA changes to dietary carbohydrate levels. Structural analysis indicated that the nine members shared conserved functional domains to the orthologues of the mammalian SOCS members, such as SRC homology 2 and the SOCS domains. Their mRNAs were constitutively expressed in various tissues but changed among the tissues. Their mRNA expression in response to dietary carbohydrate levels were explored in the liver, muscle, intestine, testis and ovary. Dietary carbohydrate addition showed significant effects on the mRNA levels of the nine SOCS members. Moreover, their mRNA expressions in response to dietary carbohydrate levels were also tissue-dependent. These indicated that SOCS members potentially mediated the utilization of dietary carbohydrate in yellow catfish.

Zinc reduces hepatic lipid deposition and activates lipophagy via Zn2+/MTF-1/PPARα and Ca2+/CaMKKß/AMPK pathways.

Zinc (Zn) deficiency is the most consistently discovered nutritional manifestations of fatty liver disease. Although Zn is known to stimulate hepatic lipid oxidation, little is known about its underlying mechanism of action in lipolysis. Given the potential role of lipophagy in lipid metabolism, the purpose of this study was to test the hypothesis that Zn attenuates hepatic lipid accumulation by modulating lipophagy. The present study indicated that Zn is a potent promoter of lipophagy. Zn administration significantly alleviated hepatocellular lipid accumulation and increased the release of free fatty acids in association with enhanced fatty acid oxidation and inhibited lipogenesis, which was accompanied by activation of autophagy. Moreover, Zn reduced lipid accumulation and stimulated lipolysis by autophagy-mediated lipophagy. Zn-induced up-regulation of autophagy and lipid depletion is free Zn2+-dependent in the cytosols. Zn-induced autophagy and lipid turnover involved up-regulation of the calcium/calmodulin-dependent protein kinase kinase-ß (Ca2+/CaMKKß)/AMPK pathway. Meanwhile, Zn2+-activated autophagy and lipid depletion were via enhancing metal response element-binding transcription factor (MTF)-1 DNA binding at PPARα promoter region, which in turn induced transcriptional activation of the key genes related to autophagy and lipolysis. Zn activated the pathways of Zn2+/MTF-1/ Peroxisome proliferator-activated receptor (PPAR)α and Ca2+/CaMKKß/AMPK, resulting in the up-regulation of lipophagy and accordingly reduced hepatic lipid accumulation. Our study, for the first time, provided innovative evidence of the direct relationship between metal elements (Zn) and lipid metabolism. The present study also indicated the novel mechanism for Zn-induced lipolysis by the activation of Zn2+/MTF-1/PPARα and Ca2+/CaMKKß/AMPK pathways, which induced the occurrence of lipophagy. These results provide new insight into Zn nutrition and its potential beneficial effects on the prevention of fatty liver disease in vertebrates.-Wei, C.-C., Luo, Z., Hogstrand, C., Xu, Y.-H., Wu, L.-X., Chen, G.-H., Pan, Y.-X., Song, Y.-F. Zinc reduces hepatic lipid deposition and activates lipophagy via Zn2+/MTF-1/PPARα and Ca2+/CaMKKß/AMPK pathways.