👤 Yachan Ning

MicroRNAs (miRNAs) are involved in many biological activities including immune defense against pathogens. In this study, we applied high-throughput sequencing technology to examine miRNAs in Japanese flounder (Paralichthys olivaceus) infected with Streptococcus iniae at different times. A total of 1038 miRNAs were identified, of which, 249 were novel miRNAs, and 81 showed differential expression (named DEmiRNAs) after S. iniae infection. Of the 81 DEmiRNAs identified, 34 and 58 occurred at 6 h and 24 h post-infection, respectively; most DEmiRNAs were strongly time-specific, and only 13.6% of the DEmiRNAs were shared between the two time points. A total of 9582 target genes were predicted for the 81 DEmiRNAs. The putative target genes were enriched in various GO and KEGG pathways of biological processes and molecular/cellular functions, in particular endocytosis, regulation of transcription, lysososme, and the signaling pathways of MAPK, ErbB, and AMPK. One of the DEmiRNAs, pol-3p-10740₁₇₅, was found to target dual specificity phosphatase 6 (Dusp6) and repress the expression of the latter. Transfection of flounder FG cells with pol-3p-10740₁₇₅ caused a significant inhibition on S. iniae invasion. The results of this study provided the first S. iniae-induced miRNA profile in Japanese flounder and indicated that flounder miRNAs play an important role in antibacterial immunity. Show less

MicroRNAs (miRNAs) have been validated to play prominent roles in the occurrence and development of anaplastic thyroid carcinoma (ATC). miR-199a-5p was previously reported to act as a tumor suppressor or oncomiRNA in various types of cancer. However, its accurate expression, function, and mechanism in ATC remain unclear. Here, we find that miR-199a-5p is significantly downregulated in ATC tissues compared with adjacent non-cancerous tissues. Overexpression of miR-199a-5p significantly inhibits migration and invasion of ATC cells in vitro, and lung metastasis in vivo. Importantly, miR-199a-5p suppresses epithelial-mesenchymal transition (EMT) both in vitro and in vivo by targeting Snail. Taken together, this study reveals that miR-199a-5p is critical to the EMT progression in ATC cells. Targeting the pathway described here may be a novel approach for inhibiting metastasis of ATC. Show less

Studies have shown that a normal circadian rhythm is crucial to learning and memory. Circadian rhythm disturbances that occur at early stages of Alzheimer's disease (AD) aggravate the progression of the disease and further reduce learning and memory in AD patients. The novel, dual GLP-1R/GIPR agonist DA-JC1 has been found to exert a stronger hypoglycemic effect than a GLP-1R agonist alone and has been shown to exert neuroprotective effects. However, it is not clear whether DA-JC1 improves the Aβ31-35-induced decline in learning and memory ability by restoring disrupted circadian rhythms. In the present study, we carried out a mouse wheel-running experiment and Morris water maze test (MWM) and found that DA-JC1 could effectively improve the decline of learning and memory and circadian rhythm disorders induced by Aβ31-35. After downregulating Per2 expression via lentivirus-shPer2 in the hippocampus and the hippocampal HT22 cells, we found that circadian rhythm disorders occurred, and that DA-JC1 could not improve the impaired learning and memory. These results suggest that DA-JC1 improves damage to learning and memory by antagonizing circadian rhythm disorders induced by Aβ31-35. The outcome of this ongoing study may provide a novel therapeutic intervention for AD in the future. Show less

ANGPTL4 (angiopoietin-like 4) is a secreted protein involved in triacylglycerol homeostasis. It is a key enzyme in lipolysis, which stimulates the oxidation of fatty acids and inhibits fat accumulation by inhibiting the activity of lipoprotein lipase (LPL). Using quantitative Real-Time PCR (qRT-PCR) to investigate the mRNA expression pattern of the bovine ANGPTL4 gene in different tissues and organs, we found that bovine ANGPTL4 had the highest expression level in the liver followed by subcutaneous adipose tissue. To clarify the molecular mechanism involved in the regulation of bovine ANGPTL4, we identified the transcriptional start site (TSS) of the ANGPTL4 gene and obtained 2011 bp of the 5' regulatory region. A series of 5' deletion promoter luciferase reporter assays revealed that the minimum functional promoter region of bovine ANGPTL4 was located at -568 bp to -261 bp relative to TSS. Two transcription factors, GR and Foxa1, were identified and considered as important transcriptional activators of ANGPTL4 by mutational analysis and RNA interference assays in combination with electrophoretic mobility shift assays (EMSA) in bovines. In conclusion, GR and Foxa1 were determined to be responsible for the regulation of ANGPTL4 transcription. Our results may provide a basis for further investigation of ANGPTL4 regulation and a reference for improvement of beef quality in cattle. Show less

Activation of endothelial β-catenin signaling by neural cell-derived Norrin or Wnt ligands is vital for the vascularization of the retina and brain. Mutations in members of the Norrin/β-catenin pathway contribute to inherited blinding disorders because of defective vascular development and dysfunctional blood-retina barrier. Despite a vital role for endothelial β-catenin signaling in central nervous system health and disease, its contribution to central nervous system angiogenesis and its interactions with downstream signaling cascades remains incompletely understood. Approach and Results: Here, using genetically modified mouse models, we show that impaired endothelial β-catenin signaling caused hypovascularization of the postnatal retina and brain because of deficient endothelial cell proliferation and sprouting. Mosaic genetic analysis demonstrated that endothelial β-catenin promotes but is not required for tip cell formation. In addition, pharmacological treatment revealed that angiogenesis under conditions of inhibited Notch signaling depends upon endothelial β-catenin. Importantly, impaired endothelial β-catenin signaling abrogated the expression of the VEGFR (vascular endothelial growth factor receptor)-2 and VEGFR3 in brain microvessels but not in the lung endothelium. Our study identifies molecular crosstalk between the Wnt/β-catenin and the Notch and VEGF-A signaling pathways and strongly suggest that endothelial β-catenin signaling supports central nervous system angiogenesis by promoting endothelial cell sprouting, tip cell formation, and VEGF-A/VEGFR2 signaling. Show less

Recent studies implicate a strong association between elevated plasma branched-chain amino acids (BCAAs) and insulin resistance (IR). However, a causal relationship and whether interrupted BCAA homeostasis can serve as a therapeutic target for diabetes remain to be established experimentally. In this study, unbiased integrative pathway analyses identified a unique genetic link between obesity-associated IR and BCAA catabolic gene expression at the pathway level in human and mouse populations. In genetically obese ( Show less

Chromobox (CBX) proteins are important components of epigenetic regulation complexes known to play key roles in hepatocellular carcinoma (HCC). Little is known about the function of distinct CBXs in HCC. To address this issue, the study investigated the roles of CBXs in the prognosis of HCC using ONCOMINE, UALCAN, Human Protein Atlas, Kaplan-Meier Plotter, Show less

Type 2 diabetes mellitus is often treated with insulin-sensitizing drugs called thiazolidinediones (TZD), which improve insulin resistance and glycemic control. Despite their effectiveness in treating diabetes, these drugs provide little protection from eminent cardiovascular disease associated with diabetes. Here we demonstrate how chiglitazar, a configuration-restricted non-TZD peroxisome proliferator-activated receptor (PPAR) pan agonist with moderate transcription activity, preferentially regulates Show less

17β-Hydroxysteroid dehydrogenase type 3 (17β-HSD3) is expressed almost exclusively in the testes and specifically converts the weak androgenic androstenedione to active testosterone (T) in the presence of NADPH. Additionally, studies have demonstrated that 17β-HSD3 is over-expressed in hormone-dependent prostate cancer. T, which interacts with the androgen receptor (AR), eventually stimulates the growth of prostate cancer cells. Defects in T synthesis or action impair the development of the male phenotype during embryogenesis and cause the autosomal recessive disorder male pseudohermaphroditism. Affected individuals are often born with female-appearing external genitalia and are reared as females. Since 17β-HSD3 plays a central role in T production, it has been recognized as a promising therapeutic target to reduce the circulating level of androgens and to suppress androgen-sensitive tumor proliferation. In recent decades, improvements have been made in the development of 17β-HSD3 inhibitors. Herein, we give an overview of the main structure and function of human 17β-HSD3 and summarize steroidal and non-steroidal inhibitors of 17β-HSD3, which can be a potential target for prostate cancer. Show less

Gene fusion is one of the hallmarks of cancer. Recent advances in RNA-seq of cancer transcriptomes have facilitated the discovery of fusion transcripts. In this study, we report identification of a surprisingly large number of fusion transcripts, including six Show less

A large meta-analysis recently identified six new loci associated with risk of PD, but subsequent studies have given discrepant results. Here we conducted a case-control study in a Han Chinese population in an attempt to clarify risk associations in Chinese. Among the four single-nucleotide polymorphisms (SNPs) that we examined - VPS13C-rs2414739, MIR4697-rs329648, GCH1-rs11158026, and SIPA1L2- rs10797576 we detected a significant association between rs329648 and risk of developing PD in a recessive model. This association remained significant after adjusting for gender and age (OR 1.87, 95%CI 1.295-2.694, p=8.21×10 Show less

For adaptation to complex cellular functions, dynamic cytoskeletal networks are required. There are two major components of the cytoskeleton, microtubules and actin filaments, which form an intricate network maintaining an exquisite cooperation to build the physical basis for their cellular function. However, little is known about the molecular mechanism underlying their synergism. Here, we show that in Caco2 epithelial cells, noncentrosomal microtubules crosstalk with F-actin through their minus ends and contribute to the regulation of focal adhesion size and cell migration. We demonstrate that ACF7, a member of the spectraplakin family of cytoskeletal crosslinking proteins, interacts with Nezha (also called CAMSAP3) at the minus ends of noncentrosomal microtubules and anchors them to actin filaments. Those noncentrosomal microtubules cooperate with actin filaments through retrograde flow to keep their length and orientation perpendicular to the cell edge as well as regulate focal adhesion size and cell migration. Show less

The primary cilium plays critical roles in vertebrate development and physiology, but the mechanisms underlying its biogenesis remain poorly understood. We investigated the molecular function of C2 calcium-dependent domain containing 3 (C2cd3), an essential regulator of primary cilium biogenesis. We show that C2cd3 is localized to the centriolar satellites in a microtubule- and Pcm1-dependent manner; however, C2cd3 is dispensable for centriolar satellite integrity. C2cd3 is also localized to the distal ends of both mother and daughter centrioles and is required for the recruitment of five centriolar distal appendage proteins: Sclt1, Ccdc41, Cep89, Fbf1, and Cep164. Furthermore, loss of C2cd3 results in failure in the recruitment of Ttbk2 to the ciliary basal body as well as the removal of Cp110 from the ciliary basal body, two critical steps in initiating ciliogenesis. C2cd3 is also required for recruiting the intraflagellar transport proteins Ift88 and Ift52 to the mother centriole. Consistent with a role in distal appendage assembly, C2cd3 is essential for ciliary vesicle docking to the mother centriole. Our results suggest that C2cd3 regulates cilium biogenesis by promoting the assembly of centriolar distal appendages critical for docking ciliary vesicles and recruiting other essential ciliogenic proteins. Show less

Free fatty acids (FFAs) are reported to be related to coronary heart disease (CHD); however, some case subjects in those reports suffered from CHD and diabetes mellitus. The aim of this research was to reveal the FFAs as the independent discriminators in non-diabetic CHD patients. The association between FFA concentrations and DNA methylation of carbohydrate response element binding protein (ChREBP) was also investigated, since ChREBP acted as an important regulatory factor in the FFA synthesis. Blood samples were collected after an overnight fast from 60 controls and 68 non-diabetic patients with CHD. Plasma concentrations of glucose, cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol (HDL-C), and low density lipoprotein cholesterol (LDL-C) were measured by standard techniques in an automatic biochemical analyzer. Plasma concentrations of nine types of FFAs were determined by high performance liquid chromatography (HPLC). The DNA methylation of ChREBP was detected by direct bisulfate sequencing. In the case group, the concentrations of glucose and HDL-C decreased, while the concentrations of TC, TG, and each FFA significantly increased compared with controls (p < 0.05). By logistic regression analysis, all FFAs except C14:0 were found to be independent risk factors for CHD in non-diabetic patients. No significant differences of clinical chemistry indicators were found between the methylated and unmethylated case groups. Plasma concentrations of FFAs are higher in non-diabetic patients with CHD and are emerging independent discriminators for CHD. High FFA concentrations are expected to play a role even in non-diabetic patients with CHD. Show less

Birth weight reflects prenatal metabolic adaption and has been related to later-life obesity risk. This study aimed to evaluate whether birth weight modifies the effect of genetic susceptibility on obesity risk in young Chinese. We recruited 540 young (14-30 years) and obese patients (body mass index, BMI30 kg m(-2)), and 500 age- and sex-matched normal-weight healthy individuals (BMI<23 kg m(-2)). We genotyped 23 BMI-associated genetic variants identified from recent genome-wide association studies (GWAS) in Caucasians with European ancestry with minor allele frequency>0.05 in HapMap Han Chinese in Beijing, China. Six loci, including SEC16B, GNPDA2, BDNF, FTO, MC4R and TMEM160, were significantly associated with obesity risk, with odds ratio from 1.314 to 1.701. The 23 risk loci accounted for 6.38% of the genetic variance in obesity. We created two genetic risk scores (GRSs) by summing the risk alleles of all 23 (GRS1) and 6 obesity-associated (GRS2) genetic variants. Prediction of obesity was significantly improved (P<0.001) when the GRS1 and GRS2 were added to a model with age and gender, with improvement of discrimination for obesity by 0.8% and 2.7%, respectively. In addition, we found that the two GRSs interacted with birth weight in relation to obesity (Pinteraction<0.001). The genetic effect appeared to be more pronounced in individuals with normal range of birth weight (25-75%) than those with either low (<25%) or high (>75%) birth weight. We confirmed the associations of the single-nucleotide polymorphism tagging six loci reported in recent GWAS with obesity in young Chinese. Our data also suggest birth weight may significantly modify genetic susceptibility to obesity risk. Show less

Familial aggregation of hepatocellular carcinoma (HCC), the third leading cause of cancer death worldwide, has shown to be a common phenomenon. We investigated the association between the genetic background and HCC familial aggregation. Serum samples were collected from HCC family members and normal control family members for screening the differentially expressed protein peaks with the approach of surface-enhanced laser desorption ionization time-of-flight mass spectrometry. Potential genetically associated protein peaks were selected and further identified by matrix assisted laser desorption ionization-time of flight mass spectrometry. A panel of six protein peaks (m/z 6432.94, 8478.35, 9381.91, 17284.67, 17418.34, and 18111.04) were speculated to reflect the genetic susceptibility of HCC familial aggregation. Three of them (m/z 6432.94, 8478.35, and 9381.91) were selected to identify as the candidate proteins. Nine identified proteins, including mostly apolipoprotein family (ApoA1, ApoA2, ApoC3, ApoE) and serum amyloid A protein (SAA), were found overexpressed in the multiple HCC cases family members. The comparative proteomic profiles have suggested that genetic factors ought to be taken into account for familial aggregation of HCC. Show less

Accumulated mast cells in atherosclerotic plaques secrete a high level of tryptase that may participate in the pathogenesis of atherosclerotic disease by diverse pathways. However, the role of tryptase in the lipid metabolism of macrophages remains to be defined. In the present study, we found that the addition of tryptase into THP-1-derived macrophages increased both intracellular lipid accumulation and total cholesterol level. Tryptase promoting foam cell formation was also observed by transmission electron microscope. These effects were resisted by APC366, a selective inhibitor of mast cell tryptase. Tryptase dramatically resisted 22RHC induced activation of LXRalpha protein expression, which can be reversed by SAM-11 (a PAR-2-specific neutralizing antibody) and reduced LXRalpha, ABCG1, ABCA1 and SREBP-1c mRNA levels and ABCG1 protein level, which were all blocked by APC366. PAR-2 agonist also redeemed 22RHC stimulation to activate LXRalpha, ABCG1 protein expression, and mRNA levels of LXRalpha and its target genes in both THP-1-derived macrophages and primary human monocyte-derived macrophages. In primary macrophages that were first transfected with PAR-2 siRNA and then treated with tryptase, both the ABCG1 protein level and mRNA levels of LXRalpha and ABCG1 were higher than those in the control siRNA-treated cells. Taken together, our data clarified the PAR-2 expression of human macrophages and suggested that tryptase might promote lipid accumulation in macrophages and foam cell formation by suppressing LXRalpha activation via PAR-2/LXRalpha/LXRalpha target genes signaling pathway. This investigation sheds a new light on the role of tryptase in foam cell formation and pathogenesis of atherosclerosis. Show less

Hyperlipidemia is one of the most important risk factors for atherosclerosis. This can be amplified by a localized inflammatory response mediated by macrophages. Macrophages are capable of taking up excess cholesterol, and it is well known that delivery of cholesterol to the mitochondria by steroidogenic acute regulatory (StAR) protein is the rate-limiting step for cholesterol degradation in the liver. It has also been shown that overexpression of StAR in hepatocytes dramatically increases the amount of regulatory oxysterols in the nucleus, which play an important role in the maintenance of intracellular lipid homeostasis. The goal of the present study was to determine whether StAR plays a similar role in macrophages. We have found that overexpression of StAR in human THP-1 monocyte-derived macrophages decreases intracellular lipid levels, activates liver X receptor alpha (LXRalpha) and proliferation peroxysome activator receptor gamma (PPARgamma), and increases ABCG1 and CYP27A1 expression. Furthermore, it reduces the secretion of inflammatory factors, and prevents apoptosis. These results suggest that StAR delivers cholesterol to mitochondria where regulatory oxysterols are generated. Regulatory oxysterols can in turn activate nuclear receptors, which increase expression of cholesterol efflux transporters, and decrease secretion of inflammatory factors. These effects can prevent macrophage apoptosis. These results imply a potential role of StAR in the prevention of atherosclerosis. Show less