WWP2 is a ubiquitin E3 ligase belonging to the Nedd4-like family. Given that WWP2 target proteins including PTEN that are crucial for regulating cell proliferation or suppressing tumorigenesis, we hav Show more
WWP2 is a ubiquitin E3 ligase belonging to the Nedd4-like family. Given that WWP2 target proteins including PTEN that are crucial for regulating cell proliferation or suppressing tumorigenesis, we have asked whether WWP2 plays a role in controlling cell cycle progression. Here we report that WWP2 is necessary for normal cell cycle progression as its silencing significantly reduces the cell proliferation rate. We have identified that an isoform of WWP2 (WWP2-V4) is highly expressed in the M phase of the cell cycle. Silencing of WWP2 accelerates the turnover of cyclin E, which is accompanied by increased levels of phospho-histone H3 (p-H3) and cyclin B. Moreover, silencing of WWP2 results in compromised phosphorylation of Akt(S473), a residue whose phosphorylation is tightly associated with the activation of the kinase. Combined, these results strongly suggest that WWP2 is an important component in regulating the Akt signaling cascade, as well as cell cycle progression. Show less
The objective of this study was to investigate the multiple relations between the preliminary molecular structural characteristics and antioxidant activities of polysaccharides from Canarium album (Lo Show more
The objective of this study was to investigate the multiple relations between the preliminary molecular structural characteristics and antioxidant activities of polysaccharides from Canarium album (Lour.) Raeusch (CPS). Three polysaccharide fractions, CPS1, CPS2, and CPS3, were isolated from CPS by column chromatography. CPS1 and CPS3 were mainly composed of neutral polysaccharides linked by α- and β-glycosidic linkages while CPS2 was pectin polysaccharides mainly linked by β-glycosidic linkages. According to the SEC-MALLS-RI system, the molecular weight of CPS1 was greater compared to CPS2 and CPS3, and the molecular weight and radius of CPS did not display positive correlation. The chain conformation analysis indicated CPS1 and CPS2 were typical highly branched polysaccharides while CPS3 existed as a globular shape in aqueous. Furthermore, the antioxidant activity of CPS2 was better than that of CPS3, while that of CPS1 was the weakest. The antioxidant activities of polysaccharide fractions were affected by their monosaccharide composition, glycosidic linkage, molecular weight, and chain conformation. This functional property was a result of a combination of multiple molecular structural factors. CPS2 was the major antioxidant component of CPS and it could be exploited as a valued antioxidant product. The molecular structural characteristics, antioxidant activities, and structure-function relationships of polysaccharide fractions from Canarium album were first investigated in this study. The results provided background and practical knowledge for the deep-processed products of C. album with high added value. CPS2 was the major antioxidant component of CPS, which could be exploited as a valued antioxidant ingredient in food and pharmaceutical industries. Show less
To investigate whether activation of liver X receptors (LXRs) protects N-methyl-D-aspartic (NMDA)-induced retinal neurotoxicity in mice and to explore the underlying mechanism. Inner retinal damage wa Show more
To investigate whether activation of liver X receptors (LXRs) protects N-methyl-D-aspartic (NMDA)-induced retinal neurotoxicity in mice and to explore the underlying mechanism. Inner retinal damage was induced by intravitreal injection of NMDA. A synthetic LXR ligand TO901317 (TO90, 50 mg/kg/d) or vehicle was intragastrically administrated from 3 days before to 1 day or 7 days after NMDA injection. The severity of retinal damage was evaluated with histological analysis and TUNEL staining, and retinal functions were evaluated by ERG. The expressions of caspase-3, bax, bcl-2, TNF-α, and BACE1, the rate-limiting enzyme in the formation of amyloid β (Aβ), in the retina were examined by real-time PCR and ELISA. The levels of LXRs, NF-κB subunit p65, p-p38 mitogen-activated protein kinase (MAPK), and an LXR target gene ABCA1 were detected with real-time PCR and Western blotting. The localization and protein expression of Aβ in the retina was assessed by immunohistochemistry and Western blotting. The NMDA enhanced the expression of LXRβ but not LXRα and ABCA1 in mouse retina. Nevertheless, administration of TO90 after NMDA injection not only enhanced the expression of LXRβ but also upregulated the level of ABCA1, suggesting retinal LXRs were activated in a ligand-dependent manner. The LXRα expression was unchanged in the vehicle and the TO90-treated groups. Activation of LXRβ with TO90 inhibited cell death in the ganglion cell layer (GCL) and inner nuclear layer (INL), preserved ERG b- and a-wave amplitudes, and the b/a ratio in the NMDA-treated mice. Meanwhile, TO90 suppressed the elevation of apoptosis factors caspase-3 and bax induced by NMDA and upregulated the level of an antiapoptotic factor bcl-2. The TO90 also inhibited the increase of p-p38 MAPK and proinflammatory cytokine TNF-α after NMDA injection. Furthermore, activation of LXR attenuated the activation of NF-κB, and reduced gene expression of BACE1 and accumulation of Aβ induced by NMDA. Activation of LXRβ with a synthetic LXR ligand TO90 protects the inner retinal damage induced by NMDA in mice. We speculate the protective effect is associated with inhibition of the NF-κB signaling pathway and reduction of Aβ formation in retina. The LXR agonists may become a new class of neuroprotective agent for retinal diseases associated with glutamate-induced excitotoxicity. Show less
Rapsyn, a scaffold protein, is required for the clustering of acetylcholine receptors (AChRs) at contacts between motor neurons and differentiating muscle cells. Rapsyn is also expressed in cells that Show more
Rapsyn, a scaffold protein, is required for the clustering of acetylcholine receptors (AChRs) at contacts between motor neurons and differentiating muscle cells. Rapsyn is also expressed in cells that do not express AChRs. However, its function in these cells remains unknown. Here, we show that rapsyn plays an AChR-independent role in organizing the distribution and mobility of lysosomes. In cells devoid of AChRs, rapsyn selectively induces the clustering of lysosomes at high density in the juxtanuclear region without affecting the distribution of other intracellular organelles. However, when the same cells overexpress AChRs, rapsyn is recruited away from lysosomes to colocalize with AChR clusters on the cell surface. In rapsyn-deficient (Rapsn(-/-)) myoblasts or cells overexpressing rapsyn mutants, lysosomes are scattered within the cell and highly dynamic. The increased mobility of lysosomes in Rapsn(-/-) cells is associated with a significant increase in lysosomal exocytosis, as evidenced by increased release of lysosomal enzymes and plasma membrane damage when cells were challenged with the bacterial pore-forming toxin streptolysin-O. These findings uncover a new link between rapsyn, lysosome positioning, exocytosis and plasma membrane integrity. Show less
Endothelial dysfunction, common in chronic kidney disease (CKD), significantly increases cardiovascular disease risk in CKD patients. This study investigates whether different vitamin D receptor agoni Show more
Endothelial dysfunction, common in chronic kidney disease (CKD), significantly increases cardiovascular disease risk in CKD patients. This study investigates whether different vitamin D receptor agonists exhibit different effects on endothelial function and on aortic gene expression in an animal CKD model. The 5/6 nephrectomized (NX) rat was treated with or without alfacalcidol (0.02, 0.04 and 0.08μg/kg), paricalcitol (0.04 and 0.08μg/kg), or VS-105 (0.004, 0.01 and 0.16μg/kg). All three compounds at the test doses suppressed serum parathyroid hormone effectively. Alfacalcidol at 0.08μg/kg raised serum calcium significantly. Endothelial function was assessed by pre-contracting thoracic aortic rings with phenylephrine, followed by treatment with acetylcholine or sodium nitroprusside. Uremia significantly affected endothelial-dependent aortic relaxation, which was improved by all three compounds in a dose-dependent manner with alfacalcidol and paricalcitol exhibiting a lesser effect. DNA microarray analysis of aorta samples revealed that uremia impacted the expression of numerous aortic genes, many of which were normalized by the vitamin D analogs. Real-time RT-PCR analysis confirmed that selected genes such as Abra, Apoa4, Fabp2, Hsd17b2, and Hspa1b affected by uremia were normalized by the vitamin D analogs with alfacalcidol exhibiting less of an effect. These results demonstrate that different vitamin D analogs exhibit different effects on endothelial function and aortic gene expression in 5/6 NX rats. This article is part of a Special Issue entitled '17th Vitamin D Workshop'. Show less
The additional mutational complexity associated with copy number variation (CNV) can provide important clues as to the underlying mechanisms of CNV formation. Correct annotation of the additional muta Show more
The additional mutational complexity associated with copy number variation (CNV) can provide important clues as to the underlying mechanisms of CNV formation. Correct annotation of the additional mutational complexity is, however, a prerequisite for establishing the mutational mechanism. We illustrate this point through the characterization of a novel ∼230 kb EXT1 duplication CNV causing autosomal dominant hereditary multiple osteochondromas. Whole-genome sequencing initially identified the CNV as having a 22-bp insertion at the breakpoint junction and, unprecedentedly, multiple breakpoint-flanking micromutations on both sides of the duplication. Further investigation revealed that this genomic rearrangement had a duplication-inverted triplication-duplication structure, the inverted triplication being a 41-bp sequence synthesized from a nearby template. This permitted the identification of the sequence determinants of both the initiation (an inverted Alu repeat) and termination (a triplex-forming sequence) of break-induced replication and suggested a possible model for the repair of replication-associated double-strand breaks. Show less
Exome sequencing is a successful option for diagnosing individuals with previously uncharacterized genetic conditions, however little has been reported regarding its utility in a prenatal setting. The Show more
Exome sequencing is a successful option for diagnosing individuals with previously uncharacterized genetic conditions, however little has been reported regarding its utility in a prenatal setting. The goal of this study is to describe the results from a cohort of fetuses for which exome sequencing was performed. We performed a retrospective analysis of the first seven cases referred to our laboratory for exome sequencing following fetal demise or termination of pregnancy. All seven pregnancies had multiple congenital anomalies identified by level II ultrasound. Exome sequencing was performed on trios using cultured amniocytes or products of conception from the affected fetuses. Relevant alterations were identified in more than half of the cases (4/7). Three of the four were categorized as 'positive' results, and one of the four was categorized as a 'likely positive' result. The provided diagnoses included osteogenesis imperfecta II (COL1A2), glycogen storage disease IV (GBE1), oral-facial-digital syndrome 1 (OFD1), and RAPSN-associated fetal akinesia deformation sequence. This data suggests that exome sequencing is likely to be a valuable diagnostic testing option for pregnancies with multiple congenital anomalies detected by prenatal ultrasound; however, additional studies with larger cohorts of affected pregnancies are necessary to confirm these findings. Show less
Cryptorchidism is one of the most common congenital anomalies in newborn boys. Although the mechanism responsible for the pathophysiology of cryptorchidism has not yet been well addressed, the Wnt sig Show more
Cryptorchidism is one of the most common congenital anomalies in newborn boys. Although the mechanism responsible for the pathophysiology of cryptorchidism has not yet been well addressed, the Wnt signaling pathway has been involved in the development of cryptorchidism. Axin1 is a central component of the Wnt signaling pathway and may play a critical role in the development of cryptorchidism. We assumed that cryptorchidism risk and the AXIN1 gene may have an association. Thus we picked out three tag SNPs (single nucleotide polymorphisms) in the AXIN1 gene and aimed to investigate whether cryptorchidism risk is associated with polymorphisms in the AXIN1 gene. The variants were discriminated using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) methods. A total of 113 cases and 179 controls were recruited to participate in this study, including 92 unilateral cryptorchidism and 21 bilateral cases. In bilateral cases, the position of the testis was decided by the higher one. A significantly increased cryptorchidism risk was found to be associated with both the T allele (p = 2e(-4), OR 1.96, 95% CI 1.37-2.78) and T/T genotype (p = 6e(-4), OR 4.00, 95% CI 1.79-9.09) of rs370681 polymorphism, and, compared with the C/C genotype, a significantly increased cryptorchidism risk was associated with the C/T-T/T genotype (p = 4e(-4), OR 2.44, 95% CI 1.47-4.00) of rs370681 polymorphisms. Among the three tag SNPs we have chosen in AXIN1, two SNPs are located in the intron region, the other SNP is located in the synonymous codon region. Evidential research has indicated that introns and other non-protein-coding RNAs may have evolved to function as network control molecules in higher organisms. Therefore, we suspected that the tag SNPs may work as controls influencing the conduct of other genes rather than affecting the structure of the protein by influencing the coding of amino acid. There were limitations in our study. One is that we did not test the expression level of Axin1. Secondly, the number of the study subjects is limited. Finally, the molecular mechanisms by which AXIN1 is involved in susceptibility to cryptorchidism should be characterized. We assessed the impact of the genetic variability of the AXIN1 gene on cryptorchidism. We have offered primary evidence that the T allele and T/T genotype of rs370681 polymorphisms and C/T genotype of rs1805105 polymorphisms in AXIN1 gene are more frequent in patients with cryptorchidism. Show less
Dickkopf1 (DKK1), a canonical Wnt/β-catenin pathway antagonist, is closely associated with cardiovascular disease and adipogenesis. We performed an in vitro study to determine whether oxidized low-den Show more
Dickkopf1 (DKK1), a canonical Wnt/β-catenin pathway antagonist, is closely associated with cardiovascular disease and adipogenesis. We performed an in vitro study to determine whether oxidized low-density lipoprotein (ox-LDL) increased the expression of DKK1 in macrophages and whether β-catenin and liver X receptor α (LXRα) were involved in this regulation. Induction of DKK1 expression by ox-LDL decreased the level of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) via a Wnt/β-catenin pathway and increased ATP-binding cassette transporter A/G1 (ABCA/G1) levels via a signal transducer and activator of transcription 3 (STAT3) pathway. Lower LOX-1 and higher ABCA/G1 levels inhibited cholesterol loading in macrophages. In conclusion, ox-LDL may induce DKK1 expression in macrophages to inhibit the accumulation of lipids through a mechanism that involves downregulation of LOX-1-mediated lipid uptake and upregulation of ABCA/G1-dependent cholesterol efflux. Show less
Microtubule actin crosslinking factor 1 (MACF1), a widely expressed cytoskeletal linker, plays important roles in various cells by regulating cytoskeleton dynamics. However, its role in osteoblastic c Show more
Microtubule actin crosslinking factor 1 (MACF1), a widely expressed cytoskeletal linker, plays important roles in various cells by regulating cytoskeleton dynamics. However, its role in osteoblastic cells is not well understood. Based on our previous findings that the association of MACF1 with F-actin and microtubules in osteoblast-like cells was altered under magnetic force conditions, here, by adopting a stable MACF1-knockdown MC3T3-E1 osteoblastic cell line, we found that MACF1 knockdown induced large cells with a binuclear/multinuclear structure. Further, immunofluorescence staining showed disorganization of F-actin and microtubules in MACF1-knockdown cells. Cell counting revealed significant decrease of cell proliferation and cell cycle analysis showed an S phase cell cycle arrest in MACF1-knockdown cells. Moreover and interestingly, MACF1 knockdown showed a potential effect on cellular MTT reduction activity and mitochondrial content, suggesting an impact on cellular metabolic activity. These results together indicate an important role of MACF1 in regulating osteoblastic cell morphology and function. Show less
Fourteen novel compounds were prepared and their antagonistic activities against liver X receptors (LXR) α/β were tested in vitro. Compound 26 had an IC50 value of 6.4 µM against LXRα and an IC50 valu Show more
Fourteen novel compounds were prepared and their antagonistic activities against liver X receptors (LXR) α/β were tested in vitro. Compound 26 had an IC50 value of 6.4 µM against LXRα and an IC50 value of 5.6 µM against LXRβ. Docking studies and the results of structure-activity relationships support the further development of this chemical series as LXRα/β antagonists. Show less
Glucose-dependent insulinotropic polypeptide (GIP) is a gut hormone secreted in response to dietary fat and glucose. The blood GIP level is elevated in obesity and diabetes. GIP stimulates proinflamma Show more
Glucose-dependent insulinotropic polypeptide (GIP) is a gut hormone secreted in response to dietary fat and glucose. The blood GIP level is elevated in obesity and diabetes. GIP stimulates proinflammatory gene expression and impairs insulin sensitivity in cultured adipocytes. In obesity, hypoxia within adipose tissue can induce inflammation. The aims of this study were 1) to examine the proinflammatory effect of increased GIP signaling in adipose tissues in vivo and 2) to clarify the association between GIP and hypoxic signaling in adipose tissue inflammation. We administered GIP intraperitoneally to misty (lean) and db/db (obese) mice and examined adipose tissue inflammation and insulin sensitivity. We also examined the effects of GIP and hypoxia on expression of the GIP receptor (GIPR) gene and proinflammatory genes in 3T3-L1 adipocytes. GIP administration increased monocyte chemoattractant protein-1 (MCP-1) expression and macrophage infiltration into adipose tissue and increased blood glucose in db/db mice. GIPR and hypoxia-inducible factor-1α (HIF-1α) expressions were positively correlated in the adipose tissue in mice. GIPR expression increased dramatically in differentiated adipocytes. GIP treatment of adipocytes increased MCP-1 and interleukin-6 (IL-6) production. Adipocytes cultured either with RAW 264 macrophages or under hypoxia expressed more GIPR and HIF-1α, and GIP treatment increased gene expression of plasminogen activator inhibitor 1 and IL-6. HIF-1α gene silencing diminished both macrophage- and hypoxia-induced GIPR expression and GIP-induced IL-6 expression in adipocytes. Thus, increased GIP signaling plays a significant role in adipose tissue inflammation and thereby insulin resistance in obese mice, and HIF-1α may contribute to this process. Show less
Recent genome-wide association studies have identified several loci influencing lipid levels. The present study focused on the triglycerides (TG)-associated locus, the APOA4-APOA5-ZNF259-BUD13 gene cl Show more
Recent genome-wide association studies have identified several loci influencing lipid levels. The present study focused on the triglycerides (TG)-associated locus, the APOA4-APOA5-ZNF259-BUD13 gene cluster on chromosome 11, to explore the role of genetic variants in this gene cluster in the development of increasing TG levels and coronary heart disease (CHD). Six single nucleotide polymorphisms (SNPs), rs4417316, rs651821, rs6589566, rs7396835, rs964184 and rs17119975, in the APOA4-APOA5-ZNF259-BUD13 gene cluster were selected and genotyped in 5374 healthy Chinese subjects. There were strong significant associations between the six SNPs and TG levels (P < 1.0 × 10(-8)). Moreover, a weighted genotype score was found to be associated with TG levels (P = 3.28 × 10(-13)). The frequencies of three common haplotypes were observed to be significantly different between the high TG group and the low TG group (P < 0.05). However, no significant effects were found for the SNPs regarding susceptibility to CHD in the Chinese case-control populations. This study highlights the genotypes, genotype scores and haplotypes of the APOA4-APOA5-ZNF259-BUD13 gene cluster that were associated with TG levels in a Chinese population; however, the genetic variants in this gene cluster did not increase the risk of CHD in the Chinese population. Show less
FADS1 (fatty acid desaturase 1) plays a crucial role in fatty acid metabolism, and it was recently reported to be involved in tumorigenesis. However, the role of FADS1 expression in esophageal squamou Show more
FADS1 (fatty acid desaturase 1) plays a crucial role in fatty acid metabolism, and it was recently reported to be involved in tumorigenesis. However, the role of FADS1 expression in esophageal squamous cell carcinoma (ESCC) remains unknown. In the current study, we investigated the expression and clinical pathologic and prognostic significance of FADS1 in ESCC. Immunohistochemical analyses revealed that 58.2% (146/251) of the ESCC tissues had low levels of FADS1 expression, whereas 41.8% (105/251) exhibited high levels of FADS1 expression. In positive cases, FADS1 expression was detected in the cytoplasm of cells. Correlation analyses demonstrated that FADS1 expression was significantly correlated with tumor location (p=0.025) but not with age, gender, histological grade, tumor status, nodal status or TNM staging. Furthermore, patients with tumors expressing high levels of FADS1had a longer disease-free survival time (p<0.001) and overall survival time (p<0.001). Univariate and multivariate analyses revealed that, along with nodal status, FADS1 expression was an independent and significant predictive factor (p<0.001). In conclusion, our study suggested that FADS1 might be a valuable biomarker and potential therapeutic target for ESCC. Show less
Both genetic predisposition and lifestyle factors are associated with the risk for obesity. Multiple obesity loci have been identified using genome-wide association studies mainly in European populati Show more
Both genetic predisposition and lifestyle factors are associated with the risk for obesity. Multiple obesity loci have been identified using genome-wide association studies mainly in European populations. The aims of this study were to examine the associations of these loci with obesity and gene×dietary behavior interactions among Chinese children and adolescents. Nineteen candidate SNPs were genotyped using Sequenom technology in the Chinese children (N=2977, 853 obese and 2124 controls, aged 7-17). Dietary behaviors were assessed using self-administered questionnaires. After adjusting for age, sex and multiple testing, MC4R rs17782313, SEC16B rs543874, MAP2K5 rs2241423 and KCTD15 rs11084753 were associated with obesity and obesity-related traits (all P<0.005), with odd ratios ranging from 1.22 to 2.15. Dose-response association was significant between genetic risk score, which was calculated by summing the risk alleles, and the risk of obesity (P<0.001). Multiplicative interaction was found between rs543874 and salt preference on obesity with an OR of 4.40 (95% CI, 1.12-17.30). Additive interactions with salt preference were found in rs17782313 and rs11084753. Our findings indicated that rs17782313, rs543874, rs2241423 and rs11084753 were associated with the risk for children obesity in China, and interaction of genetic variants with diet behaviors on obesity. Show less
During development, scaffold proteins serve as important platforms for orchestrating signaling complexes to transduce extracellular stimuli into intracellular responses that regulate dendritic spine m Show more
During development, scaffold proteins serve as important platforms for orchestrating signaling complexes to transduce extracellular stimuli into intracellular responses that regulate dendritic spine morphology and function. Axin ("axis inhibitor") is a key scaffold protein in canonical Wnt signaling that interacts with specific synaptic proteins. However, the cellular functions of these protein-protein interactions in dendritic spine morphology and synaptic regulation are unclear. Here, we report that Axin protein is enriched in synaptic fractions, colocalizes with the postsynaptic marker PSD-95 in cultured hippocampal neurons, and interacts with a signaling protein Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) in synaptosomal fractions. Axin depletion by shRNA in cultured neurons or intact hippocampal CA1 regions significantly reduced dendritic spine density. Intriguingly, the defective dendritic spine morphogenesis in Axin-knockdown neurons could be restored by overexpression of the small Rho-GTPase Cdc42, whose activity is regulated by CaMKII. Moreover, pharmacological stabilization of Axin resulted in increased dendritic spine number and spontaneous neurotransmission, while Axin stabilization in hippocampal neurons reduced the elimination of dendritic spines. Taken together, our findings suggest that Axin promotes dendritic spine stabilization through Cdc42-dependent cytoskeletal reorganization. Show less
Whether polymorphisms rs11856808 and rs9652490 of the Leucine-rich repeat and Ig domain containing, Nogo receptor-interacting protein-1 (LINGO1) gene, as well as rs10968280, rs13362909 and rs7033345 o Show more
Whether polymorphisms rs11856808 and rs9652490 of the Leucine-rich repeat and Ig domain containing, Nogo receptor-interacting protein-1 (LINGO1) gene, as well as rs10968280, rs13362909 and rs7033345 of the LINGO2 gene, increase the risk for Parkinson's disease (PD) is controversial. Considering the overlap of the clinical and pathological characteristics among PD and multiple system atrophy (MSA), we explored the associations between these five polymorphisms and PD and MSA in a Chinese population. A total of 1055 PD patients, 320 MSA patients, and 810 healthy controls (HCs) were genotyped for these five polymorphisms in LINGO1 and LINGO 2 using Sequenom iPLEX Assay technology. Moreover, after combining our results with available published data, a meta-analysis was conducted to investigate the associations between LINGO 1 rs11856808 and rs9652490 and the risk of PD. The frequency of the minor alleles "T" of LINGO1 rs11856808 was significantly lower in PD than that in HCs (p = 0.011, OR 0.89, 95 % CI 0.81-0.97), but not in MSA. Moreover, there were no significant differences in the minor allele frequency distributions of the other four polymorphisms between PD and HCs, and between MSA and HCs. The meta-analysis showed a lack of association of rs9652490 and PD, regardless of the genetic model or ethnic origin. However, the rs11856808 allele decreased the risk of PD in patients of Asian origin in a dominant genetic model. Our findings suggest that rs11856808 plays a protective role by decreasing the risk for PD, but not for MSA, in Asian population, the other four polymorphisms do not contribute to the risk for PD and MSA. Show less
MYBPC3 dysfunctions have been proven to induce dilated cardiomyopathy, hypertrophic cardiomyopathy, and/or left ventricular noncompaction; however, the genotype-phenotype correlation between MYBPC3 an Show more
MYBPC3 dysfunctions have been proven to induce dilated cardiomyopathy, hypertrophic cardiomyopathy, and/or left ventricular noncompaction; however, the genotype-phenotype correlation between MYBPC3 and restrictive cardiomyopathy (RCM) has not been established. The newly developed next-generation sequencing method is capable of broad genomic DNA sequencing with high throughput and can help explore novel correlations between genetic variants and cardiomyopathies. A proband from a multigenerational family with 3 live patients and 1 unrelated patient with clinical diagnoses of RCM underwent a next-generation sequencing workflow based on a custom AmpliSeq panel, including 64 candidate pathogenic genes for cardiomyopathies, on the Ion Personal Genome Machine high-throughput sequencing benchtop instrument. The selected panel contained a total of 64 genes that were reportedly associated with inherited cardiomyopathies. All patients fulfilled strict criteria for RCM with clinical characteristics, echocardiography, and/or cardiac magnetic resonance findings. The multigenerational family with 3 adult RCM patients carried an identical nonsense MYBPC3 mutation, and the unrelated patient carried a missense mutation in the MYBPC3 gene. All of these results were confirmed by the Sanger sequencing method. This study demonstrated that MYBPC3 gene mutations, revealed by next-generation sequencing, were associated with familial and sporadic RCM patients. It is suggested that the next-generation sequencing platform with a selected panel provides a highly efficient approach for molecular diagnosis of hereditary and idiopathic RCM and helps build new genotype-phenotype correlations. Show less
Circulating trans fatty acids (TFAs), which cannot be synthesized by humans, are linked to adverse health outcomes. Although TFAs are obtained from diet, little is known about subsequent influences (e Show more
Circulating trans fatty acids (TFAs), which cannot be synthesized by humans, are linked to adverse health outcomes. Although TFAs are obtained from diet, little is known about subsequent influences (e.g., relating to incorporation, metabolism, or intercompetition with other fatty acids) that could alter circulating concentrations and possibly modulate or mediate impacts on health. The objective was to elucidate novel biologic pathways that may influence circulating TFAs by evaluating associations between common genetic variation and TFA biomarkers. We performed meta-analyses using 7 cohorts of European-ancestry participants (n = 8013) having measured genome-wide variation in single-nucleotide polymorphisms (SNPs) and circulating TFA biomarkers (erythrocyte or plasma phospholipids), including trans-16:1n-7, total trans-18:1, trans/cis-18:2, cis/trans-18:2, and trans/trans-18:2. We further evaluated SNPs with genome-wide significant associations among African Americans (n = 1082), Chinese Americans (n = 669), and Hispanic Americans (n = 657) from 2 of these cohorts. Among European-ancestry participants, 31 SNPs in or near the fatty acid desaturase (FADS) 1 and 2 cluster were associated with cis/trans-18:2; a top hit was rs174548 (β = 0.0035, P = 4.90 × 10(-15)), an SNP previously associated with circulating n-3 and n-6 polyunsaturated fatty acid concentrations. No significant association was identified for other TFAs. rs174548 in FADS1/2 was also associated with cis/trans-18:2 in Hispanic Americans (β = 0.0053, P = 1.05 × 10(-6)) and Chinese Americans (β = 0.0028, P = 0.002) but not African Americans (β = 0.0009, P = 0.34); however, in African Americans, fine mapping identified a top hit in FADS2 associated with cis/trans-18:2 (rs174579: β = 0.0118, P = 4.05 × 10(-5)). The association between rs174548 and cis/trans-18:2 remained significant after further adjustment for individual circulating n-3 and n-6 fatty acids, except arachidonic acid. After adjustment for arachidonic acid concentrations, the association between rs174548 and cis/trans-18:2 was nearly eliminated in European-ancestry participants (β-coefficient reduced by 86%), with similar reductions in Hispanic Americans and Chinese Americans. Our findings provide novel evidence for genetic regulation of cis/trans-18:2 by the FADS1/2 cluster and suggest that this regulation may be influenced/mediated by concentrations of arachidonic acid, an n-6 polyunsaturated fat. Show less
Overexpression of 5-hydroxytryptamine (5-HT) in human cancer contributes to tumor metastasis, but the role of 5-HT receptor family in cancer has not been thoroughly explored. Here, we report overexpre Show more
Overexpression of 5-hydroxytryptamine (5-HT) in human cancer contributes to tumor metastasis, but the role of 5-HT receptor family in cancer has not been thoroughly explored. Here, we report overexpression of 5-HT(1D) receptor (5-HT(1D)R) was associated with Wnt signaling pathway and advanced tumor stage. The underlying mechanism of 5-HT(1D)R-promoted tumor invasion was through its activation on the Axin1/β-catenin/MMP-7 pathway. In an orthotopic colorectal cancer mouse model, we demonstrated that a 5-HT(1D)R antagonist (GR127935) effectively inhibited tumor metastasis through targeting Axin1. Furthermore, in intestinal epithelium cells, we observed that 5-HT(1D)R played an important role in cell invasion via Axin1/β-catenin/MMP-7 pathway. Together, our findings reveal an essential role of the physiologic level of 5-HT(1D)R in pulmonary metastasis of colorectal cancer. Show less
Cryptococcus demonstrates predilection for invasion of the brain, but the mechanism by which Cryptococcus crosses the blood-brain barrier (BBB) to cause brain invasion is largely unknown. In order for Show more
Cryptococcus demonstrates predilection for invasion of the brain, but the mechanism by which Cryptococcus crosses the blood-brain barrier (BBB) to cause brain invasion is largely unknown. In order for Cryptococcus to cross the BBB, there must be a way to either cross human brain microvascular endothelial cells, which are the main constitute of the BBB, or go in between tight junctions. Recent evidence of human brain microvascular endothelial cell responses to transcellular brain invasions includes membrane rearrangements, intracellular signaling pathways and cytoskeletal activations. Several Cryptococcal genes related to the traversal of BBB have been identified, including CPS1, ITR1a, ITR3c, PLB1, MPR1, FNX1 and RUB1. In addition, Cryptococcus neoformans-derived microvesicles may contribute to cryptococcal brain invasion. Paracellularly, Cryptococcus may traverse across BBB using either routes utilizing plasmin, ammonia or macrophages in a Trojan horse mechanism. Show less
Genome-wide association studies (GWAS) of chronic obstructive pulmonary disease (COPD) have identified disease-susceptibility loci, mostly in subjects of European descent. We hypothesized that by stud Show more
Genome-wide association studies (GWAS) of chronic obstructive pulmonary disease (COPD) have identified disease-susceptibility loci, mostly in subjects of European descent. We hypothesized that by studying Hispanic populations we would be able to identify unique loci that contribute to COPD pathogenesis in Hispanics but remain undetected in GWAS of non-Hispanic populations. We conducted a metaanalysis of two GWAS of COPD in independent cohorts of Hispanics in Costa Rica and the United States (Multi-Ethnic Study of Atherosclerosis [MESA]). We performed a replication study of the top single-nucleotide polymorphisms in an independent Hispanic cohort in New Mexico (the Lovelace Smokers Cohort). We also attempted to replicate prior findings from genome-wide studies in non-Hispanic populations in Hispanic cohorts. We found no genome-wide significant association with COPD in our metaanalysis of Costa Rica and MESA. After combining the top results from this metaanalysis with those from our replication study in the Lovelace Smokers Cohort, we identified two single-nucleotide polymorphisms approaching genome-wide significance for an association with COPD. The first (rs858249, combined P value = 6.1 × 10(-8)) is near the genes KLHL7 and NUPL2 on chromosome 7. The second (rs286499, combined P value = 8.4 × 10(-8)) is located in an intron of DLG2. The two most significant single-nucleotide polymorphisms in FAM13A from a previous genome-wide study in non-Hispanics were associated with COPD in Hispanics. We have identified two novel loci (in or near the genes KLHL7/NUPL2 and DLG2) that may play a role in COPD pathogenesis in Hispanic populations. Show less
Mammalian milk is a key source of lipids, providing not only important calories but also essential fatty acids. Veterinary medicine and omics systems sciences intersection, termed as "veterinomics" he Show more
Mammalian milk is a key source of lipids, providing not only important calories but also essential fatty acids. Veterinary medicine and omics systems sciences intersection, termed as "veterinomics" here, has received little attention to date but stands to offer much promise for building bridges between human and animal health. We determined the changes in porcine mammary genes and proteomics expression associated with milk triacylglycerol (TAG) synthesis and secretion from late pregnancy to lactation. TAG content and fatty acid (FA) composition were determined in porcine colostrum (the 1st day of lactation) and milk (the 17th day of lactation). The mammary transcriptome for 70 genes and 13 proteins involved in TAG synthesis and secretion from six sows, each at d -17(late pregnancy), d 1(early lactation), and d 17 (peak lactation) relative to parturition were analyzed using quantitative real-time PCR and Western blot analyses. The TAG content and the concentrations of de novo synthesized FAs, saturated FAs, and monounsaturated FAs were higher in milk than in colostrum (p<0.05). Robust upregulation with high relative mRNA abundance was evident during lactation for genes associated with FA uptake (VLDLR, LPL, CD36), FA activation (ACSS2, ACSL3), and intracellar transport (FABP3), de novo FA synthesis (ACACA, FASN), FA elongation (ELOVL1), FA desaturation (SCD, FADS1), TAG synthesis (GPAM, AGPAT1, LPIN1, DGAT1), lipid droplet formation (BTN2A1, XDH, PLIN2), and transcription factors and nuclear receptors (SREBP1, SCAP, INSIG1/2). In conclusion, a wide variety of lipogenic genes and proteins regulate the channeling of FAs towards milk TAG synthesis and secretion in porcine mammary gland tissue. These findings inform future omics strategies to increase milk fat production and lipid profile and attest to the rise of both veterinomics and lipidomics in postgenomics life sciences. Show less
RUNX1-RUNX1T1 (formerly AML1-ETO), a transcription factor generated by the t(8;21) translocation in acute myeloid leukemia (AML), dictates a leukemic program by increasing self-renewal and inhibiting Show more
RUNX1-RUNX1T1 (formerly AML1-ETO), a transcription factor generated by the t(8;21) translocation in acute myeloid leukemia (AML), dictates a leukemic program by increasing self-renewal and inhibiting differentiation. Here we demonstrate that the histone demethylase JMJD1C functions as a coactivator for RUNX1-RUNX1T1 and is required for its transcriptional program. JMJD1C is directly recruited by RUNX1-RUNX1T1 to its target genes and regulates their expression by maintaining low H3K9 dimethyl (H3K9me2) levels. Analyses in JMJD1C knockout mice also establish a JMJD1C requirement for RUNX1-RUNX1T1's ability to increase proliferation. We also show a critical role for JMJD1C in the survival of multiple human AML cell lines, suggesting that it is required for leukemic programs in different AML cell types through its association with key transcription factors. Show less
Understanding the consequences of tuning TCR signaling on selection, peripheral T cell function, and tolerance in the context of native TCR repertoires may provide insight into the physiological contr Show more
Understanding the consequences of tuning TCR signaling on selection, peripheral T cell function, and tolerance in the context of native TCR repertoires may provide insight into the physiological control of tolerance. In this study, we show that genetic ablation of a natural tuner of TCR signaling, mir-181a-1/b-1, in double-positive thymocytes dampened TCR and Erk signaling and increased the threshold of positive selection. Whereas mir-181a-1/b-1 deletion in mice resulted in an increase in the intrinsic reactivity of naive T cells to self-antigens, it did not cause spontaneous autoimmunity. Loss of mir-181a-1/b-1 dampened the induction of experimental autoimmune encephalomyelitis and reduced basal TCR signaling in peripheral T cells and their migration from lymph nodes to pathogenic sites. Taken together, these results demonstrate that tolerance can be modulated by microRNA gene products through the control of opposing activities in T cell selection and peripheral T cell function. Show less
Diego Ploper, Vincent F Taelman, Lidia Robert+7 more · 2015 · Proceedings of the National Academy of Sciences of the United States of America · National Academy of Sciences · added 2026-04-24
Canonical Wnt signaling plays an important role in development and disease, regulating transcription of target genes and stabilizing many proteins phosphorylated by glycogen synthase kinase 3 (GSK3). Show more
Canonical Wnt signaling plays an important role in development and disease, regulating transcription of target genes and stabilizing many proteins phosphorylated by glycogen synthase kinase 3 (GSK3). We observed that the MiT family of transcription factors, which includes the melanoma oncogene MITF (micropthalmia-associated transcription factor) and the lysosomal master regulator TFEB, had the highest phylogenetic conservation of three consecutive putative GSK3 phosphorylation sites in animal proteomes. This finding prompted us to examine the relationship between MITF, endolysosomal biogenesis, and Wnt signaling. Here we report that MITF expression levels correlated with the expression of a large subset of lysosomal genes in melanoma cell lines. MITF expression in the tetracycline-inducible C32 melanoma model caused a marked increase in vesicular structures, and increased expression of late endosomal proteins, such as Rab7, LAMP1, and CD63. These late endosomes were not functional lysosomes as they were less active in proteolysis, yet were able to concentrate Axin1, phospho-LRP6, phospho-β-catenin, and GSK3 in the presence of Wnt ligands. This relocalization significantly enhanced Wnt signaling by increasing the number of multivesicular bodies into which the Wnt signalosome/destruction complex becomes localized upon Wnt signaling. We also show that the MITF protein was stabilized by Wnt signaling, through the novel C-terminal GSK3 phosphorylations identified here. MITF stabilization caused an increase in multivesicular body biosynthesis, which in turn increased Wnt signaling, generating a positive-feedback loop that may function during the proliferative stages of melanoma. The results underscore the importance of misregulated endolysosomal biogenesis in Wnt signaling and cancer. Show less
Smooth muscle 22α (SM22α) is involved in stress fiber formation and enhances contractility in vascular smooth muscle cells (VSMCs). In many cases, SM22α acts as an adapter protein to assemble signalin Show more
Smooth muscle 22α (SM22α) is involved in stress fiber formation and enhances contractility in vascular smooth muscle cells (VSMCs). In many cases, SM22α acts as an adapter protein to assemble signaling complexes and regulate signaling, but whether SM22α regulates contractile signaling induced by angiotensin II (AngII) remains unclear. To address this issue, we established a hypertension model of Sm22α(-/-) mice, and demonstrated that hypertension induced by AngII was attenuated in Sm22α(-/-) mice. A decreased vasoconstriction was observed in aortic rings from Sm22α(-/-) mice. Furthermore, loss of SM22α resulted in a reduced contractile response to AngII in VSMCs in vitro. The phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) induced by AngII was impaired following depletion of SM22α, in parallel with a reduced contractility. The decay of ERK1/2 activity was associated with increased expression of mitogen-activated protein kinase phosphatase 3 (MKP3). Inhibition of MKP3 activity rescued ERK1/2 activity. SM22α depletion caused an enhanced interaction of MKP3 with ERK1/2, and a reduced ubiquitination and degradation of MKP3. Knockdown of SM22α extended the half-life of MKP3. In conclusion, SM22α promotes AngII-induced contraction by maintenance of ERK1/2 signaling cascades through facilitating ubiquitination and degradation of MKP3. The vasoconstriction is attenuated in aortic rings from Sm22α(-/-) mice. MKP3 mediates dephosphorylation of ERK1/2 in AngII-induced VSMC contraction. SM22α inhibits the interaction of ERK1/2 with MKP3. SM22α promotes ubiquitination and degradation of MKP3. SM22α facilitates AngII-induced contraction by maintenance of ERK1/2 signaling. Show less
Severe hypertriglyceridemia is a well-known cause of pancreatitis. Usually, there is a moderate increase in plasma triglyceride level during pregnancy. Additionally, certain pre-existing genetic trait Show more
Severe hypertriglyceridemia is a well-known cause of pancreatitis. Usually, there is a moderate increase in plasma triglyceride level during pregnancy. Additionally, certain pre-existing genetic traits may render a pregnant woman susceptible to development of severe hypertriglyceridemia and pancreatitis, especially in the third trimester. To elucidate the underlying mechanism of gestational hypertriglyceridemic pancreatitis, we undertook DNA mutation analysis of the lipoprotein lipase (LPL), apolipoprotein C2 (APOC2), apolipoprotein A5 (APOA5), lipase maturation factor 1 (LMF1), and glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1) genes in five unrelated pregnant Chinese women with severe hypertriglyceridemia and pancreatitis. DNA sequencing showed that three out of five patients had the same homozygous variation, p.G185C, in APOA5 gene. One patient had a compound heterozygous mutation, p.A98T and p.L279V, in LPL gene. Another patient had a compound heterozygous mutation, p.A98T & p.C14F in LPL and GPIHBP1 gene, respectively. No mutations were seen in APOC2 or LMF1 genes. All patients were diagnosed with partial LPL deficiency in non-pregnant state. As revealed in our study, genetic variants appear to play an important role in the development of severe gestational hypertriglyceridemia, and, p.G185C mutation in APOA5 gene appears to be the most common variant implicated in the Chinese population. Antenatal screening for mutations in susceptible women, combined with subsequent interventions may be invaluable in the prevention of potentially life threatening gestational hypertriglyceridemia-induced pancreatitis. Show less
Glycosaminoglycans are important regulators of multiple signaling pathways. As a major constituent of the heart extracellular matrix, glycosaminoglycans are implicated in cardiac morphogenesis through Show more
Glycosaminoglycans are important regulators of multiple signaling pathways. As a major constituent of the heart extracellular matrix, glycosaminoglycans are implicated in cardiac morphogenesis through interactions with different signaling morphogens. Ext1 is a glycosyltransferase responsible for heparan sulfate synthesis. Here, we evaluate the function of Ext1 in heart development by analyzing Ext1 hypomorphic mutant and conditional knockout mice. Outflow tract alignment is sensitive to the dosage of Ext1. Deletion of Ext1 in the mesoderm induces a cardiac phenotype similar to that of a mutant with conditional deletion of UDP-glucose dehydrogenase, a key enzyme responsible for synthesis of all glycosaminoglycans. The outflow tract defect in conditional Ext1 knockout(Ext1f/f:Mesp1Cre) mice is attributable to the reduced contribution of second heart field and neural crest cells. Ext1 deletion leads to downregulation of FGF signaling in the pharyngeal mesoderm. Exogenous FGF8 ameliorates the defects in the outflow tract and pharyngeal explants. In addition, Ext1 expression in second heart field and neural crest cells is required for outflow tract remodeling. Our results collectively indicate that Ext1 is crucial for outflow tract formation in distinct progenitor cells, and heparan sulfate modulates FGF signaling during early heart development. Show less
In the present study, we demonstrate that prolonged treatment by trastuzumab induced resistance of NCI-N87 gastric cancer cells to trastuzumab. The resistant cells possessed typical characteristics of Show more
In the present study, we demonstrate that prolonged treatment by trastuzumab induced resistance of NCI-N87 gastric cancer cells to trastuzumab. The resistant cells possessed typical characteristics of epithelial to mesenchymal transition (EMT)/cancer stem cells and acquired more invasive and metastatic potentials both in vitro and in vivo. Long term treatment with trastuzumab dramatically inhibited the phosphorylation of Akt, but triggered the activation of STAT3. The level of IL-6 was remarkably increased, implicating that the release of IL-6 that drives the STAT3 activation initiates the survival signaling transition. Furthermore, the Notch activities were significantly enhanced in the resistant cells, companied by upregulation of the Notch ligand Jagged-1 and the Notch responsive genes Hey1 and Hey2. Inhibiting the endogenous Notch pathway reduced the IL-6 expression and restored the sensitivities of the resistant cells to trastuzumab. Blocking of the STAT3 signaling abrogated IL-6-induced Jagged-1 expression, effectively inhibited the growth of the trastuzumab resistant cells, and enhanced the anti-tumor activities of trastuzumab in the resistant cells. These findings implicate that the IL-6/STAT3/Jagged-1/Notch axis may be a useful target and that combination of the Notch or STAT3 inhibitors with trastuzumab may prevent or delay clinical resistance and improve the efficacy of trastuzumab in gastric cancer. Show less