Pin1 Exacerbates Non-Alcoholic Fatty Liver Disease by Enhancing Its Activity through Binding to ACC1.

Non-alcoholic fatty liver disease (NAFLD) is a clinicopathological syndrome characterized by diffuse hepatocellular steatosis due to fatty deposits in hepatocytes, excluding alcohol and other known liver injury factors. However, there are no specific drugs for the clinical treatment of NAFLD. Therefore, research on the pathogenesis of NAFLD at the cellular and molecular levels is a promising approach to finding therapeutic targets and developing targeted drugs for NAFLD. Pin1 is highly expressed during adipogenesis and contributes to adipose differentiation, but its specific mechanism of action in NAFLD is unclear. In this study, we investigated the role of Pin1 in promoting the development of NAFLD and its potential mechanisms in vitro and in vivo. First, Pin1 was verified in the NAFLD model in vitro using MCD diet-fed mice by Western Blot, RT-qPCR and immunohistochemistry (IHC) assays. In the in vitro study, we used the oleic acid (OA) stimulation-induced lipid accumulation model and examined the lipid accumulation in each group of cells by oil red O staining as well as BODIPY staining. The results showed that knockdown of Pin1 inhibited lipid accumulation in hepatocytes in an in vitro lipid accumulation model and improved lipid indices and liver injury levels. Moreover, in vivo, WT and Pin1-KO mice were fed a methionine-choline deficient (MCD) diet for 4 weeks to induce the NAFLD model. The effects of Pin1 on lipid accumulation, hepatic fibrosis, and oxidative stress were evaluated by biochemical analysis, glucose and insulin tolerance tests, histological analysis, IHC, RT-qPCR and Western blot assays. The results indicate that Pin1 knockdown significantly alleviated hepatic steatosis, fibrosis and inflammation in MCD-induced NAFLD mice, improved glucose tolerance and alleviated insulin resistance in mice. Further studies showed that the AMPK/ACC1 signalling pathway might take part in the process by which Pin1 regulates NAFLD, as evidenced by the inhibition of the AMPK/ACC1 pathway. In addition, immunofluorescence (IF), coimmunoprecipitation (Co-IP) and GST pull-down experiments also showed that Pin1 interacts directly with ACC1 and inhibits ACC1 phosphorylation levels. Our study suggests that Pin1 promotes NAFLD progression by inhibiting the activation of the AMPK/ACC1 signalling pathway, and it is possible that this effect is achieved by Pin1 interacting with ACC1 and inhibiting the phosphorylation of ACC1.

HFD and HFD-provoked hepatic hypoxia act as reciprocal causation for NAFLD via HIF-independent signaling.

BACKGROUND: The occurrence of non-alcoholic fatty liver disease (NAFLD) is found to be higher in patients with obstructive sleep apnea (OSA), which is characterized by intermittent hypoxia. Activation of hypoxia-inducible factors has been shown in the development and progression of NAFLD, implying a cause and effects relationship between NAFLD and hypoxia. The present study was designed to investigate the interaction of lipotoxicity and hypoxia in the pathogenesis of NAFLD using mice model with high-fat diet (HFD) feeding or hypoxic treatment. METHODS: NAFLD model was induced in mice by HFD feeding, and in cultured primary hepatocytes by administration of palmitate acid. Mouse hypoxic model was produced by placing the mice in a Animal incubator with oxygen concentration at 75% followed by a 21% oxygen supplement. Hypoxic condition was mimicked by treating the hepatocytes with cobalt chloride (CoCl2) or 1% oxygen supply. Pimonidazole assay was conducted to evaluate hypoxia. Lipid metabolic genes were measured by real-time polymerase-chain reaction. HIF-1α and HIF-2α genes were silenced by siRNA. RESULTS: HFD feeding and palmitate acid treatment provoked severe hepatic hypoxia along with TG accumulation in mice and in cultured primary hepatocytes respectively. Conversely, hypoxia induced hepatic TG accumulation in mice and in cultured primary hepatocytes. Hypoxic treatment inhibited the expression of lipolytic genes, while increased the expression of lipogenicgenes in mice. Although both lipotoxicity and hypoxia could activate hepatic hypoxia-induced factor 1α and 2α, while neither lipotoxicity- nor hypoxia- induced hepatic steatosis was affected when HIF was knocked down. CONCLUSIONS: HFD resulted in hepatic TG accumulation and concomitant hypoxia. Conversely, hypoxia induced hepatic TG accumulation in mice and in cultured heptocytes. Thus lipotoxicity and hypoxia might work as reciprocal causation and orchestrate to promote the development of NAFLD.

Estrogen restores disordered lipid metabolism in visceral fat of prediabetic mice.

BACKGROUND: Visceral obesity is increasingly prevalent among adolescents and young adults and is commonly recognized as a risk factor for type 2 diabetes. Estrogen [17ß-estradiol (E2)] is known to offer protection against obesity via diverse me-chanisms, while its specific effects on visceral adipose tissue (VAT) remain to be fully elucidated. AIM: To investigate the impact of E2 on the gene expression profile within VAT of a mouse model of prediabetes. METHODS: Metabolic parameters were collected, encompassing body weight, weights of visceral and subcutaneous adipose tissues (VAT and SAT), random blood glucose levels, glucose tolerance, insulin tolerance, and overall body composition. The gene expression profiles of VAT were quantified utilizing the Whole Mouse Genome Oligo Microarray and subsequently analyzed through Agilent Feature Extraction software. Functional and pathway analyses were conducted employing Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses, respectively. RESULTS: Feeding a high-fat diet (HFD) moderately increased the weights of both VAT and SAT, but this increase was mitigated by the protective effect of endogenous E2. Conversely, ovariectomy (OVX) led to a significant increase in VAT weight and the VAT/SAT weight ratio, and this increase was also reversed with E2 treatment. Notably, OVX diminished the expression of genes involved in lipid metabolism compared to HFD feeding alone, signaling a widespread reduction in lipid metabolic activity, which was completely counteracted by E2 administration. This study provides a comprehensive insight into E2's local and direct protective effects against visceral adiposity in VAT at the gene level. CONCLUSION: In conclusion, the present study demonstrated that the HFD-induced over-nutritional challenge disrupted the gene expression profile of visceral fat, leading to a universally decreased lipid metabolic status in E2 deficient mice. E2 treatment effectively reversed this condition, shedding light on the mechanistic role and therapeutic potential of E2 in combating visceral obesity.

Agaricus bisporus-derived ß-glucan enter macrophages and adipocytes by CD36 receptor.

ß-glucans are a heterogeneous group of natural polysaccharides. They are ubiquitously found in bacterial or fungal cell walls, cereals, seaweed, and mushrooms. The beneficial role of ß-glucan in tumor, insulin resistance, dyslipidemia, hypertension, and obesity is being continuously documented. Ample evidence showed that ß-glucan could act on several receptors, such as Dectin, complement receptor (CR3), TLR-2, 4, 6 and scavenger. Based on the above, we wanted to explore whether agaricus bisporus-derived ß-glucan acted on these receptors on Raw 264.7 macrophages and 3T3-L1 adipocytes.

Lysimachia Capillipes Inhibit Adipogenesis via Angiogenesis Inhibition.

Obesity is a common and increasingly prevalent human condition due to unhealthy diet and less-exercise lifestyle. Development of obesity is associated with substantial modulation of adipose tissue structure. The expansion of adipose tissue is linked to the development of its vasculature, and modulation of angiogenesis may have the potential to impair adipose tissue development. In this study, we used obesity model of zebrafish fed by egg yolk to investigate the effect of Lysimachia capillipes on the obesity. The results showed that Lysimachia capillipes inhibited angiogenesis of adipose tissue in transgenic zebrafish Tg (Fli 1: EGFP), which was similar to surppressing effect of TNP-470, which was accompanied by decreased Oil Red O staining of the zebrafish. The treatment of Lysimachia capillipes reduced expression of MTP significantly, but modestly reduced expression of Ppar g, FABP10a, and CD36 level through ISH, which was accordant with the results by PCR analysis. The study proved that Lysimachia capillipes might possess novel therapeutic properties for prevention and treatment of obesity.

Higher plasma concentration of TP53-induced glycolysis and apoptosis regulator is associated with a lower risk of colorectal cancer metastasis.

PURPOSE: We aimed to explore the association of plasma TP53-induced glycolysis and apoptosis regulator (TIGAR) level with colorectal cancer (CRC) metastasis. METHODS: A cross-sectional study of 126 CRC patients was conducted in Xiamen, China. Multivariable logistic regression was used to calculate adjusted OR and 95% CIs of plasma TIGAR concentration for CRC metastasis in different models with adjustment for potential confounders. Area under the curve (AUC) of receiver operating characteristic (ROC) curve was used to evaluate the diagnostic value. RESULTS: CRC patients with metastasis showed significantly decreased plasma TIGAR concentration compared to their controls (1.97±0.64 vs 2.49±0.69 ng/mL [log transformed], P=0.002). Higher plasma TIGAR was significantly associated with the decreased risk of CRC metastasis, and the adjusted OR (95% CI) was 0.134 (0.027-0.676, P=0.015) for per SD increase in plasma TIGAR concentration, and the trend test for increasing tertiles showed a negative trend of plasma TIGAR on risk of CRC metastasis (P for trend test: 0.005). Pearson correlation coefficients of plasma TIGAR with other cancer biomarkers (carbohydrate antigen 50 [CA50], carbohydrate antigen 199 [CA199], carbohydrate antigen 125 [CA125], carbohydrate antigen 724 [CA724], carcinoembryonic antigen [CEA], and ferritin [FER]) was low (P>0.05). AUC (95% CI) of ROC curve of plasma TIGAR for CRC metastasis was comparable to the values of cancer biomarkers (all P-values <0.05). CONCLUSION: Higher level of plasma TIGAR was significantly and independently associated with lower risk of CRC metastasis, and its prognostic value on CRC metastasis was comparable to the common cancer biomarkers.

Agaricus bisporus-derived ß-glucan prevents obesity through PPAR γ downregulation and autophagy induction in zebrafish fed by chicken egg yolk.

ß-(1,4)-d-Glucan with (1,2) and (1,6)-linked branches (short for ß-glucan), extracted from Agaricus bisporus (Lange) Sing, had significant anti-obesity and lowering-fat effect. FITC-ß-glucan was absorbed by adipocytes of zebrafish larvae when stained by Nile Red. ß-Glucan decreased the adiposity mass, reduced the expression of ppar g, mtp, L-fabp, ifabp in ISH, which was coincident as the results of RT-PCT. ß-Glucan lowered the level of C/EBP α, c SREBP1, LXR α, PPAR γ by WB analysis, which were accompanied by an increase level in LC3 II/LC3 I and a decline level in p62 in dose-dependent manner. This study explored the effect and mechanisms of Agaricus bisporus derived-ß-glucan to regulate lipid metabolism and prevent lipid deposits, and provided the experimental data for its use in diet food and food addictive.

Anti-inflammatory effects of guggulsterone on murine macrophage by inhibiting LPS-induced inflammatory cytokines in NF-κB signaling pathway.

The present study was aimed to investigate the effects of guggulsterone (GS) on proinflammatory responses as well as the underlying molecular mechanisms in macrophage upon lipopolysaccharide (LPS) stimulation. Effects of GS on viability of Raw264.7 cells were examined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Real-time polymerase chain reaction (PCR) was employed to examine the mRNA expression of cytokines, including interleukin 1ß (IL-1ß), tumor necrosis factor-alpha (TNF-α), and inducible nitric oxide synthase (iNOS). Phosphorylations of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinases (p38), and inhibitor of nuclear factor kappaB (IκB) were determined using immunoblotting. The results revealed that GS was not toxic to Raw264.7 cells at designated concentrations. We demonstrated that GS significantly suppressed the elevated mRNA expression of proinflammatory cytokines, including IL-1ß, TNF-α, and iNOS in a dose-dependent manner. GS treatment reduced the level of IκB phosphorylation in LPS-stimulated macrophages in a dose-dependent manner. Use of BAY 11-7082, an inhibitor of nuclear factor-kappaB (NF-κB), led to significantly suppressing effects on IL-1ß and TNF-α expression similar as that of GS-treated cells. Our findings suggest that GS possesses anti-inflammatory activity, which may be attributed to downregulation of iNOS and inhibition of NF-κB activity in LPS-stimulated Raw264.7 cells.

Fructus xanthii improves lipid homeostasis in the epididymal adipose tissue of rats fed a high-fat diet.

High fat diet (HFD)-induced obesity triggers common features of human metabolic syndrome in rats. Our previous study showed that Fructus xanthii (FX) attenuates HFD-induced hepatic steatosis. The present study was designed to investigate the effects of FX on lipid metabolism in epididymal fat (EF), and examine its underlying mechanisms. Aqueous extraction fractions of FX or vehicle were orally administered by gavage for 6 weeks to rats fed either a HFD or a normal chow diet (NCD). The levels of circulating free fatty acid (FFA) were determined in plasma, and the expression levels of lipid metabolism­ and inflammation­associated genes in the EF were measured using reverse transcription­quantitative polymerase chain reaction analysis. The general morphology, size and number of adipocytes in the EF, and the levels of macrophage infiltration were evaluated using hematoxylin and eosin staining or immunohistochemical staining. FX decreased circulating levels of FFA, increased the expression levels of sterol­regulatory­element­binding protein­1c, FAS, acetyl coenzyme A carboxylase, diacylglycerol acyltransferase and lipoprotein lipase lipogenic genes in the EF. FX increased the numbers of adipocytes in the EF, and featured a shift towards smaller adipocyte size. Compared with the vehicle­treated rats, positive staining of F4/80 was more dispersed in the FX­treated rats, and the percentage of F4/80 positive cells was significantly decreased. FX attenuated HFD­induced lipid dyshomeostasis in the epididymal adipose tissue.

Puerarin protects pancreatic ß-cell survival via PI3K/Akt signaling pathway.

Pancreatic ß-cell loss because of apoptosis is the major cause of type 1 diabetes (T1D) and late stage T2D. Puerarin possesses anti-diabetic properties; whether it acts directly on pancreatic ß-cell is not clear. This study was designed to investigate the effects of puerarin on pancreatic ß-cell survival and function. Diabetes was induced in male C57BL/6 mice by a single peritoneal injection of streptozotocin (STZ). Pancreatic ß-cell survival and function were assessed in diabetic mice by measuring ß-cell apoptosis, ß-cell mass, pancreatic insulin content, and glucose tolerance, and in cultured islets and clonial MIN6 ß-cells by measuring ß-cell viability and apoptosis and glucose-stimulated insulin secretion. We found that pre-treatment with puerarin decreased the incidence of STZ-induced diabetes. Puerarin increased pancreatic ß-cell mass via ß-cell apoptosis inhibition in diabetic mice, and increased serum insulin, whereas it decreased blood glucose levels and improved glucose tolerance. In cultured islets and MIN6 cells, puerarin protected ß-cell from cobalt chloride (CoCl2)-induced apoptosis and restored the impaired capacity of glucose-stimulated insulin secretion. Puerarin protection of ß-cell survival involved the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway. In conclusion, puerarin protects pancreatic ß-cell function and survival via direct effects on ß-cells, and its protection of ß-cell survival is mediated by the PI3K/Akt pathway. As a safe natural plant extraction, puerarin might serve as a preventive and/or therapeutic approach for diabetes.