The mouse alpha-albumin (afamin) promoter is differentially regulated by hepatocyte nuclear factor 1α and hepatocyte nuclear factor 1β

Circulating afamin positively correlated with the miR-122 expression and type 2 diabetes mellitus-related phenotype according to the duration of diabetes

Background

Afamin is a hepatokine that involves in glucose and lipids metabolism. miR-122 is mainly expressed in liver and involves in lipid and carbohydrate metabolism. This study aimed at investigating the circulating afamin, its correlation with type 2 diabetes mellitus (T2DM) and miR-122 gene expression in T2DM patients and healthy control subjects according to the duration of diabetes.

Methods

This case-control study included 220 participants, with 100 individuals serving as controls and 120 individuals diagnosed with type 2 diabetes mellitus (T2DM). The miR-122 gene expression was assessed using real-time PCR. The serum concentration of biochemical parameters such as glucose levels, lipid profile, and small-dense low-density lipoprotein (sdLDL) were measured using colorimetric kits. Circulating afamin and insulin levels were assayed using an ELISA kit. Glycated hemoglobin (HbA1c) was measured using capillary electrophoresis.

Results

Circulating afamin level was significantly higher in T2DM patients compared to the control group, (73.8 ± 10.8 vs. 65.9 ± 8.7, respectively; P < 0.001). Similarly, miR122 expression was significantly increased in T2DM patients compared to healthy control subjects (4.24 ± 2.01 vs. 1.00 ± 0.85, respectively; P < 0.001). Among patients diagnosed with T2DM, those with longstanding diabetes (>5 years) exhibited significantly higher levels of circulating afamin and miR-122 expression compared to individuals with a shorter duration of diabetes (≤5 years) (P < 0.05). Circulating afamin levels were significantly correlated with waist circumference, small-dense low-density lipoprotein (sdLDL), fasting blood sugar (FBS), insulin, resistance to insulin, and miR-122 expression, depending on the duration of the disease (P < 0.05). Furthermore, the performance of afamin as a diagnostic marker for T2DM was confirmed through receiver operating characteristic (ROC) analysis, yielding an area under the curve (AUC) of 0.7 (P < 0.001).

Conclusions

Circulating afamin involved in the T2DM-related complications and its concentration is positively correlated to the miR-122 expression, especially in patient with longstanding diabetes.

Asperulosidic Acid Ameliorates Renal Interstitial Fibrosis via Removing Indoxyl Sulfate by Up-Regulating Organic Anion Transporters in a Unilateral Ureteral Obstruction Mice Model

Asperulosidic acid is a bioactive iridoid isolated from Hedyotis diffusa Willd. with anti-inflammatory and renal protective effects. However, its mechanism on renal interstitial fibrosis has not been elucidated yet. The present study aims to explore whether asperulosidic acid could retard renal fibrosis by reducing the circulating indoxyl sulfate (IS), which is a uremic toxin and accelerates chronic kidney disease progression by inducing renal fibrosis. In this paper, a unilateral ureteral obstruction (UUO) model of Balb/C mice was established. After the mice were orally administered with asperulosidic acid (14 and 28 mg/kg) for two weeks, blood, liver and kidney were collected for biochemical, histological, qPCR and Western blot analyses. Asperulosidic acid administration markedly reduced the serum IS level and significantly alleviated the histological changes in glomerular sclerosis and renal interstitial fibrosis. It is noteworthy that the mRNA and protein levels of the organic anion transporter 1 (OAT1), OAT3 and hepatocyte nuclear factor 1α (HNF1α) in the kidney were significantly increased, while the mRNA expressions of cytochrome P450 2e1 (Cyp2e1) and sulfotransferase 1a1 (Sult1a1) in the liver were not altered after asperulosidic acid administration. These results reveal that asperulosidic acid could accelerate the renal excretion of IS by up-regulating OATs via HNF1α in UUO mice, thereby alleviating renal fibrosis, but did not significantly affect its production in the liver, which might provide important information for the development of asperulosidic acid.

Hyaluronic acid-entecavir conjugates-core/lipid-shell nanohybrids for efficient macrophage uptake and hepatotropic prospects

Drug covalently bound to polymers had formed, lately, platforms with great promise in drug delivery. These drug polymer conjugates (DPC) boosted drug loading and controlled medicine release with targeting ability. Herein, the ability of entecavir (E) conjugated to hyaluronic acid (HA) forming the core of vitamin E coated lipid nanohybrids (EE-HA LPH), to target Kupffer cells and hepatocyte had been proved. The drug was associated to HA with efficiency of 93.48 ± 3.14 % and nanohybrids loading of 22.02 ± 2.3 %. DiI labelled lipidic nanohybrids improved the macrophage uptake in J774 cells with a 21 day hepatocytes retention post intramuscular injection. Finally, in vivo biocompatibility and safety with respect to body weight, organs indices and histopathological alterations were demonstrated. Coating with vitamin E and conjugation of E to HA (a CD44 ligand), could give grounds for prospective application for vectored nano-platform in hepatitis B.

Serum Afamin a Novel Marker of Increased Hepatic Lipid Content

AIM

Afamin is a liver-produced glycoprotein, a potential early marker of metabolic syndrome. Here we investigated regulation of afamin in a course of the metabolic disease development and in response to 3-month exercise intervention.

METHODS

We measured whole-body insulin sensitivity (euglycemic hyperinsulinemic clamp), glucose tolerance, abdominal adiposity, hepatic lipid content (magnetic resonance imaging/spectroscopy), habitual physical activity (accelerometers) and serum afamin (enzyme-linked immunosorbent assay) in 71 middle-aged men with obesity, prediabetes and newly diagnosed type 2 diabetes. Effects of 3-month exercise were investigated in 22 overweight-to-obese middle-aged individuals (16M/6F).

RESULTS

Prediabetes and type 2 diabetes, but not obesity, were associated with increased serum afamin (p<0.001). Afamin correlated positively with hepatic lipids, fatty liver index and liver damage markers; with parameters of adiposity (waist circumference, %body fat, adipocyte diameter) and insulin resistance (fasting insulin, C-peptide, HOMA-IR; p<0.001 all). Moreover, afamin negatively correlated with whole-body insulin sensitivity (M-value/Insulin, p<0.001). Hepatic lipids and fasting insulinemia were the most important predictors of serum afamin, explaining >63% of its variability. Exercise-related changes in afamin were paralleled by reciprocal changes in insulinemia, insulin resistance and visceral adiposity. No significant change in hepatic lipid content was observed.

CONCLUSIONS

Subjects with prediabetes and type 2 diabetes had the highest serum afamin levels. Afamin was more tightly related to hepatic lipid accumulation, liver damage and insulin resistance than to obesity.

New insights into the role of HNF-1β in kidney (patho)physiology

Hepatocyte nuclear factor-1β (HNF-1β) is an essential transcription factor that regulates the development and function of epithelia in the kidney, liver, pancreas, and genitourinary tract. Humans who carry HNF1B mutations develop heterogeneous renal abnormalities, including multicystic dysplastic kidneys, glomerulocystic kidney disease, renal agenesis, renal hypoplasia, and renal interstitial fibrosis. In the embryonic kidney, HNF-1β is required for ureteric bud branching, initiation of nephrogenesis, and nephron segmentation. Ablation of mouse Hnf1b in nephron progenitors causes defective tubulogenesis, whereas later inactivation in elongating tubules leads to cyst formation due to downregulation of cystic disease genes, including Umod, Pkhd1, and Pkd2. In the adult kidney, HNF-1β controls the expression of genes required for intrarenal metabolism and solute transport by tubular epithelial cells. Tubular abnormalities observed in HNF-1β nephropathy include hyperuricemia with or without gout, hypokalemia, hypomagnesemia, and polyuria. Recent studies have identified novel post-transcriptional and post-translational regulatory mechanisms that control HNF-1β expression and activity, including the miRNA cluster miR17 ∼ 92 and the interacting proteins PCBD1 and zyxin. Further understanding of the molecular mechanisms upstream and downstream of HNF-1β may lead to the development of new therapeutic approaches in cystic kidney disease and other HNF1B-related renal diseases.

Target delivery of small interfering RNAs with vitamin E-coupled nanoparticles for treating hepatitis C

RNA interference (RNAi) represents a promising strategy for the treatment of HCV infection. However, the development of an effective system for in vivo delivery of small interfering RNA (siRNA) to target organ remains a formidable challenge. Here, we develop a unique nanoparticle platform (VE-DC) composed of α-tocopherol (vitamin E) and cholesterol-based cationic liposomes (DOTAP-Chol) for systemic delivery of siRNAs to the liver. A HCV-replicable cell line, Huh7.5.1-HCV, and a transient HCV core expressing cell line, Huh7.5.1-Core, were constructed and used to assess the in vitro anti-HCV activity of VE-DC/siRNAs. A transient in vivo HCV model was also constructed by hydrodynamic injection of pCDNA3.1(+)-3FLAG-Core (pCore-3FLAG) plasmid expressing core protein or pGL3-5′UTR-luciferase (pGL3-5′UTR-luc) plasmid expressing luciferase driven by HCV 5′UTR. Nanoscale VE-DC/siRNA was intravenously injected to assess the liver-targeting property as well as antiviral activity. The nanoscale VE-DC effectively exerted an anti-HCV activity in the in vitro cell models. Post-administration of VE-DC/siRNAs also effectively delivered siRNAs to the liver, suppressing core protein production and firefly luciferase activity, without inducing an innate immunity response or off-target and toxicity effects. The VE-DC platform has high potential as a vehicle for delivery of siRNAs to the liver for gene therapy for targeting hepatitis C.

Development of a Lac Operon Concept Inventory (LOCI)

Concept inventories (CIs) are valuable tools for educators that assess student achievement and identify misconceptions held by students. Results of student responses can be used to adjust or develop new instructional methods for a given topic. The regulation of gene expression in both prokaryotes and eukaryotes is an important concept in genetics and one that is particularly challenging for undergraduate students. As part of a larger study examining instructional methods related to gene regulation, the authors developed a 12-item CI assessing student knowledge of the lac operon. Using an established protocol, the authors wrote open-ended questions and conducted in-class testing with undergraduate microbiology and genetics students to discover common errors made by students about the lac operon and to determine aspects of item validity. Using these results, we constructed a 12-item multiple-choice lac operon CI called the Lac Operon Concept Inventory (LOCI), The LOCI was reviewed by two experts in the field for content validity. The LOCI underwent item analysis and was assessed for reliability with a sample of undergraduate genetics students (n = 115). The data obtained were found to be valid and reliable (coefficient alpha = 0.994) with adequate discriminatory power and item difficulty.

Afamin--A pleiotropic glycoprotein involved in various disease states

The human glycoprotein afamin was discovered as the fourth member of the albumin gene family. Despite intense research over the last 20 years, our knowledge of afamin's physiological or pathophysiological functions is still very limited. Circulating afamin is primarily of hepatic origin and abundant concentrations are found in plasma, cerebrospinal, ovarian follicular and seminal fluids. In vitro binding studies revealed specific binding properties for vitamin E. A previously performed analytical characterization and clinical evaluation study of an enzyme-linked immunosorbent assay for quantitative measurement of afamin in human plasma demonstrated that the afamin assay meets the quality specifications for laboratory medicine. Comparative proteomics has identified afamin as a potential biomarker for ovarian cancer and these findings were confirmed by quantitative immunoassay of afamin and validated in independent cohorts of patients with ovarian cancer. Afamin has also been investigated in other types of carcinoma. Most of these studies await further evaluation with validated quantitative afamin assays and require validation in larger patient cohorts. Transgenic mice overexpressing the human afamin gene revealed increased body weight and increased blood concentrations of lipids and glucose. These transgenic mouse data were in line with three large human population-based studies showing that afamin is strongly associated with the prevalence and development of the metabolic syndrome. This review summarizes and discusses the molecular, biochemical and analytical characterization of afamin as well as possible clinical applications of afamin measurement.

Systems genetics of liver fibrosis: identification of fibrogenic and expression quantitative trait loci in the BXD murine reference population

The progression of liver fibrosis in response to chronic injury varies considerably among individual patients. The underlying genetics is highly complex due to large numbers of potential genes, environmental factors and cell types involved. Here, we provide the first toxicogenomic analysis of liver fibrosis induced by carbon tetrachloride in the murine ‘genetic reference panel’ of recombinant inbred BXD lines. Our aim was to define the core of risk genes and gene interaction networks that control fibrosis progression. Liver fibrosis phenotypes and gene expression profiles were determined in 35 BXD lines. Quantitative trait locus (QTL) analysis identified seven genomic loci influencing fibrosis phenotypes (pQTLs) with genome-wide significance on chromosomes 4, 5, 7, 12, and 17. Stepwise refinement was based on expression QTL mapping with stringent selection criteria, reducing the number of 1,351 candidate genes located in the pQTLs to a final list of 11 cis-regulated genes. Our findings demonstrate that the BXD reference population represents a powerful experimental resource for shortlisting the genes within a regulatory network that determine the liver's vulnerability to chronic injury.

Pericentral activity of alpha-fetoprotein enhancer 3 and glutamine synthetase upstream enhancer in the adult liver are regulated by β-catenin in mice

We previously showed that mouse alpha-fetoprotein (AFP) enhancer 3 activity is highly restricted to pericentral hepatocytes in the adult liver. Here, using transgenic mice, we show that the upstream enhancer of the rat glutamine synthetase gene is also active, specifically in pericentral regions. Activity of both enhancers is lost in the absence of β-catenin, a key regulator of zonal gene expression in the adult liver. Both enhancers contain a single, highly conserved T-cell factor/lymphoid enhancer factor binding site that is required for responsiveness to β-catenin. We also show that endogenous AFP messenger RNA levels in the perinatal liver are lower when β-catenin is reduced.

CONCLUSION

These data identify the first distinct zonally active regulatory regions required for β-catenin responsiveness in the adult liver, and suggest that postnatal AFP repression and the establishment of zonal regulation are controlled, at least in part, by the same factors.

Diagnosis, management, and prognosis of HNF1B nephropathy in adulthood

Mutations in HNF1B are responsible for a dominantly inherited disease with renal and nonrenal consequences, including maturity-onset diabetes of the young (MODY) type 5. While HNF1B nephropathy is typically responsible for bilateral renal cystic hypodysplasia in childhood, the adult phenotype is poorly described. To help define this we evaluated the clinical presentation, imaging findings, genetic changes, and disease progression in 27 adults from 20 families with HNF1B nephropathy. Whole-gene deletion was found in 11 families, point mutations in 9, and de novo mutations in half of the kindred tested. Renal involvement was extremely heterogeneous, with a tubulointerstitial profile at presentation and slowly progressive renal decline throughout adulthood as hallmarks of the disease. In 24 patients tested, there were cysts (≤5 per kidney) in 15, a solitary kidney in 5, hypokalemia in 11, and hypomagnesemia in 10 of 16 tested, all as characteristics pointing to HNF1B disease. Two patients presented with renal Fanconi syndrome and, overall, 4 progressed to end-stage renal failure. Extrarenal phenotypes consisted of diabetes mellitus in 13 of the 27 patients, including 11 with MODY, abnormal liver tests in 8 of 21, diverse genital tract abnormalities in 5 of 13 females, and infertility in 2 of 14 males. Thus, our findings provide data that are useful for recognition and diagnosis of HNF1B disease in adulthood and might help in renal management and genetic counseling.

Zhx2 and Zbtb20: novel regulators of postnatal alpha-fetoprotein repression and their potential role in gene reactivation during liver cancer

The mouse alpha-fetoprotein (AFP) gene is abundantly expressed in the fetal liver, normally silent in the adult liver but is frequently reactivated in hepatocellular carcinoma. The basis for AFP expression in the fetal liver has been studied extensively. However, the basis for AFP reactivation during hepatocarcinogenesis is not well understood. Two novel factors that control postnatal AFP repression, Zhx2 and Zbtb20, were recently identified. Here, we review the transcription factors that regulate AFP in the fetal liver, as well as Zhx2 and Zbtb20, and raise the possibility that the loss of these postnatal repressors may be involved in AFP reactivation in liver cancer.