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
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
Cyclosporine A (CsA) increases β-catenin messenger RNA (mRNA) and protein expression. The present study demonstrates that Wnt/β-catenin signaling inhibits β-catenin degradation in the gingiva. Forty 5 Show more
Cyclosporine A (CsA) increases β-catenin messenger RNA (mRNA) and protein expression. The present study demonstrates that Wnt/β-catenin signaling inhibits β-catenin degradation in the gingiva. Forty 5-week-old male Sprague-Dawley rats were assigned to two study groups after healing from right maxillary molar extractions. The rats in the experimental group were fed 30 mg/kg CsA daily for 4 weeks, whereas the control rats were fed mineral oil. At the end of the study, all rats were sacrificed, and the gingivae were obtained. The gingival morphology after CsA treatment was evaluated by histology, and the genes related to Wnt/β-catenin signaling were initially screened by microarray. Polymerase chain reaction, Western blotting, and immunohistochemistry were used to examine the mRNA and protein expression of proliferating cell nuclear antigen, cyclin D1, E-cadherin, β-catenin, Dvl-1, glycogen synthase kinase-3β, axin-1, and adenomatous polyposis coli (APC). Phosphoserine and ubiquitinylated β-catenin were detected after immunoprecipitation. In rats treated with CsA, overgrowth of gingivae was observed, and altered expression of genes related to Wnt/β-catenin signaling was detected by the microarray. The gingival mRNA and protein expression profiles for genes associated with Wnt/β-catenin signaling further confirmed the effect of CsA: β-catenin and Dvl-1 expression increased, but APC and axin-1 expression decreased. Western blotting and immunohistochemistry showed decreases in β-catenin serine phosphorylation (33/37) and ubiquitinylation in the gingivae of CsA-treated rats. CsA-enhanced gingival β-catenin stability may be involved in gene upregulation or β-catenin degradation via the Wnt/β-catenin pathway. 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
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
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
Ammonia detoxification is essential for physiological well-being, and the urea cycle in liver plays a predominant role in ammonia disposal. Nobiletin (NOB), a natural dietary flavonoid, is known to ex Show more
Ammonia detoxification is essential for physiological well-being, and the urea cycle in liver plays a predominant role in ammonia disposal. Nobiletin (NOB), a natural dietary flavonoid, is known to exhibit various physiological efficacies. In the current study, we investigated a potential role of NOB in ammonia control and the underlying cellular mechanism. C57BL/6 mice were fed with regular chow (RC), high-fat (HFD) or high-protein diet (HPD) and treated with either vehicle or NOB. Serum and/or urine levels of ammonia and urea were measured. Liver expression of genes encoding urea cycle enzymes and C/EBP transcription factors was determined over the circadian cycle. Luciferase reporter assays were carried out to investigate function of CCAAT consensus elements on the carbamoyl phosphate synthetase (Cps1) gene promoter. A circadian clock-deficient mouse mutant, Clock (Δ19/Δ19) , was utilized to examine a requisite role of the circadian clock in mediating NOB induction of Cps1. NOB was able to lower serum ammonia levels in mice fed with RC, HFD or HPD. Compared with RC, HFD repressed the mRNA and protein expression of Cps1, encoding the rate-limiting enzyme of the urea cycle. Interestingly, NOB rescued CPS1 protein levels under the HFD condition via induction of the transcription factors C/EBPα and C/EBPβ. Expression of other urea cycle genes was also decreased by HFD relative to RC and again restored by NOB to varying degrees, which, in conjunction with Cps1 promoter reporter analysis, suggested a C/EBP-dependent mechanism for the co-induction of urea cycle genes by NOB. In comparison, HPD markedly increased CPS1 levels relative to RC, yet NOB did not further enrich CPS1 to a significant extent. Using the circadian mouse mutant Clock (Δ19/Δ19) , we also showed that a functional circadian clock, known to modulate C/EBP and CPS1 expression, was required for NOB induction of CPS1 under the HFD condition. NOB, a dietary flavonoid, exhibits a broad activity in ammonia control across varying diets, and regulates urea cycle function via C/EBP-and clock-dependent regulatory mechanisms. Show less
To evaluate whether the Chinese Han population harbors genetic markers associated with risk of acute myocardial infarction (MI), which have previously been identified in other ethnic populations. Acco Show more
To evaluate whether the Chinese Han population harbors genetic markers associated with risk of acute myocardial infarction (MI), which have previously been identified in other ethnic populations. According to predefined criteria, 549 Chinese patients with acute MI and 551 Chinese subjects (controls) without a history of coronary artery disease (CAD) were selected for the study. Three prevalent single nucleotide polymorphisms (SNPs; rs1412444(LIPA), rs662799(APOA5) and rs964184(ZNF259)) associated with CAD and MI in other ethnic populations, were selected for sequence and association analyses within blood DNA of the Chinese Han population. Only two SNPs, rs662799 (APOA5) and rs964184 (ZNF259) found at two independent loci, were associated with risk of MI in the Chinese Han population. Using Bonferroni correction methods, significant differences in the association of these two SNPs (rs662799 (p = 0.0228) and rs964184 (p = 0.0060)) between Chinese patients with MI versus controls were revealed. We identified a significant association between two SNPs (rs964184 and rs662799) on chromosome 11q23.3 and MI risk in the Chinese Han population, which extends their clinical relevance to predicting the risk of MI in diverse ethnic populations. Show less
Here, we investigated the role of LXRα in capsaicin mediated anti-inflammatory effects. Results revealed that capsaicin inhibits LPS-induced IL-1β, IL-6 and TNF-α production in a time- and dose-depend Show more
Here, we investigated the role of LXRα in capsaicin mediated anti-inflammatory effects. Results revealed that capsaicin inhibits LPS-induced IL-1β, IL-6 and TNF-α production in a time- and dose-dependent manner. Moreover, capsaicin increases LXRα expression through PPARγ pathway. Inhibition of LXRα activation by siRNA diminished the inhibitory action of capsaicin on LPS-induced IL-1β, IL-6 and TNF-α production. Additionally, LXRα siRNA abrogated the inhibitory action of capsaicin on p65 NF-κB protein expression. Thus, we propose that the anti-inflammatory effects of capsaicin are LXRα dependent, and LXRα may potentially link the capsaicin mediated PPARγ activation and NF-κB inhibition in LPS-induced inflammatory response. Show less
Little is known about the association of the FADS1/FADS2 SNPs and serum lipid levels and the risk of coronary artery disease (CAD) and ischemic stroke (IS) in the Chinese southern population. The pres Show more
Little is known about the association of the FADS1/FADS2 SNPs and serum lipid levels and the risk of coronary artery disease (CAD) and ischemic stroke (IS) in the Chinese southern population. The present study aimed to determine such association in the Chinese southern population. A total of 1,669 unrelated subjects (CAD, 534; IS, 553; and healthy controls, 582) were recruited in the study. Genotypes of the FADS1 rs174546 SNP and the FADS2 rs174601 SNP were determined by the SNaPshot Multiplex Kit. The T allele and TT genotype frequencies of the two SNPs were predominant in our study population. The T alleles were associated with increased risk of CAD and IS. Correspondingly, the C alleles were associated with reduced risk of CAD and IS. Haplotype analyses showed that the haplotype of T-T (rs174546-rs174601) was associated with an increased risk for IS, and the haplotype of C-C (rs174546-rs174601) was associated with a reduced risk for CAD and IS. The two SNPs were likely to influence serum lipid levels. The T allele carriers of the two SNPs and rs174601 TT genotype were associated with decreased serum HDL-C and ApoAI levels in the patient groups and with an increased risk of CAD and IS. The present study suggests that the FADS1 rs174546 SNP and the FADS2 rs174601 SNP are associated with the risk of CAD and IS, and are likely to influence serum lipid levels. However, further functional studies are needed to clarify how the two SNPs actually affect serum lipid levels and the risk of CAD and IS. 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
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
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
WW domains harbor substrates containing proline-rich motifs, but the substrate specificity and binding mechanism remain elusive for those WW domains less amenable for structural studies, such as human Show more
WW domains harbor substrates containing proline-rich motifs, but the substrate specificity and binding mechanism remain elusive for those WW domains less amenable for structural studies, such as human WWP2 (hWWP2). Herein we have employed multiple techniques to investigate the second WW domain (WW2) in hWWP2. Our results show that hWWP2 is a specialized E3 for PPxY motif-containing substrates only and does not recognize other amino acids and phospho-residues. The strongest binding affinity of WW2, and the incompatibility between each WW domain, imply a novel relationship, and our SPR experiment reveals a dynamic binding mode in Class-I WW domains for the first time. The results from alanine-scanning mutagenesis and modeling further point to functionally conserved residues in WW2. Show less
Etomidate is a rapid hypnotic intravenous anesthetic agent. The major side effect of etomidate is the reduced plasma concentration of corticosteroids, leading to the abnormal reaction of adrenals. Cor Show more
Etomidate is a rapid hypnotic intravenous anesthetic agent. The major side effect of etomidate is the reduced plasma concentration of corticosteroids, leading to the abnormal reaction of adrenals. Cortisol and testosterone biosynthesis has similar biosynthetic pathway, and shares several common steroidogenic enzymes, such as P450 side chain cleavage enzyme (CYP11A1) and 3β-hydroxysteroid dehydrogenase 1 (HSD3B1). The effect of etomidate on Leydig cell steroidogenesis during the cell maturation process is not well established. Immature Leydig cells isolated from 35 day-old rats were cultured with 30 μM etomidate for 3 hours in combination with LH, 8Br-cAMP, 25R-OH-cholesterol, pregnenolone, progesterone, androstenedione, testosterone and dihydrotestosterone, respectively. The concentrations of 5α-androstanediol and testosterone in the media were measured by radioimmunoassay. Leydig cells were cultured with various concentrations of etomidate (0.3-30 μM) for 3 hours, and total RNAs were extracted. Q-PCR was used to measure the mRNA levels of following genes: Lhcgr, Scarb1, Star, Cyp11a1, Hsd3b1, Cyp17a1, Hsd17b3, Srd5a1, and Akr1c14. The testis mitochondria and microsomes from 35-day-old rat testes were prepared and used to detect the direct action of etomidate on CYP11A1 and HSD3B1 activity. In intact Leydig cells, 30 μM etomidate significantly inhibited androgen synthesis. Further studies showed that etomidate also inhibited the LH- stimulated androgen production. On purified testicular mitochondria and ER fractions, etomidate competitively inhibited both CYP11A1 and HSD3B1 activities, with the half maximal inhibitory concentration (IC50) values of 12.62 and 2.75 μM, respectively. In addition, etomidate inhibited steroidogenesis-related gene expression. At about 0.3 μM, etomidate significantly inhibited the expression of Akr1C14. At the higher concentration (30 μM), it also reduced the expression levels of Cyp11a1, Hsd17b3 and Srd5a1. In conclusion, etomidate directly inhibits the activities of CYP11A1 and HSD3B1, and the expression levels of Cyp11a1 and Hsd17b3, leading to the lower production of androgen by Leydig cells. 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
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
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
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
Dual-specificity phosphatase 6 (DUSP6) is a negative feedback mechanism of the mitogen-activated protein (MAP) kinase superfamily (MAPK/ERK, SAPK/JNK, p38), that is associated with cellular proliferat Show more
Dual-specificity phosphatase 6 (DUSP6) is a negative feedback mechanism of the mitogen-activated protein (MAP) kinase superfamily (MAPK/ERK, SAPK/JNK, p38), that is associated with cellular proliferation and differentiation. It has been reported that the expression of DUSP6 in different types of breast cancer is diverse and therefore it has altered functions in various types of breast cancer. Our aim was to explore the exact function of DUSP6 in triple-negative breast cancer cells (MDA-MB-231 cell) and to determine whether the suppression of DUSP6 by small interfering RNA (siRNA) and mircroRNA (miRNA) inhibits the growth of human MDA-MB-231 breast cancer cells. DUSP6-siRNA was used to inhibit the expression of DUSP6 directly and miR-145 to inhibit the expression of DUSP6 either in MDA-MB-231 breast cancer cells and successful transfection being confirmed by Real-time PCR and Western Blotting. Down regulation of DUSP6 in MDA-MB-231 cells suppressed the cell proliferation as investigated by MTT assay and colony form assay. Transwell test and Scratch assay were conducted to investigate the migration and invasion of MDA-MB-231 cells. T-test (two-tailed) was used to compare differences between groups, and the significance level was set at P<0.05. DUSP6 mRNA expression and protein expression were reduced after transfection with DUSP6-siRNA directly and similar trend with transfection with miR-145. The treated group with DUSP6-siRNA or miR-145 suppressed MDA-MB-231 cells proliferation, migration and invasion, and meanwhile the cells were arrested at G0/G1 phase. DUSP6 plays a role in triple-negative breast cancer cells that might promote growth in MDA-MB-231 triple-negative breast cancer cells. 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
Phytochrome-interacting factor 3 (PIF3) activates light-responsive transcriptional network genes in coordination with the circadian clock and plant hormones to modulate plant growth and development. H Show more
Phytochrome-interacting factor 3 (PIF3) activates light-responsive transcriptional network genes in coordination with the circadian clock and plant hormones to modulate plant growth and development. However, little is known of the roles PIF3 plays in the responses to abiotic stresses. In this study, the cloning and functional characterization of the ZmPIF3 gene encoding a maize PIF3 protein is reported. Subcellular localization revealed the presence of ZmPIF3 in the cell nucleus. Expression patterns revealed that ZmPIF3 is expressed strongly in leaves. This expression responds to polyethylene glycol, NaCl stress, and abscisic acid application, but not to cold stress. ZmPIF3 under the control of the ubiquitin promoter was introduced into rice. No difference in growth and development between ZmPIF3 transgenic and wild-type plants was observed under normal growth conditions. However, ZmPIF3 transgenic plants were more tolerant to dehydration and salt stresses. ZmPIF3 transgenic plants had increased relative water content, chlorophyll content, and chlorophyll fluorescence, as well as significantly enhanced cell membrane stability under stress conditions. The over-expression of ZmPIF3 increased the expression of stress-responsive genes, such as Rab16D, DREB2A, OSE2, PP2C, Rab21, BZ8 and P5CS, as detected by real-time PCR analysis. Taken together, these results improve our understanding of the role ZmPIF3 plays in abiotic stresses signaling pathways; our findings also indicate that ZmPIF3 regulates the plant response to drought and salt stresses. 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
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
Familial hypertrophic cardiomyopathy (HCM) is attributed to mutations in genes that encode for the sarcomere proteins, especially Mybpc3 and Myh7. Genotype-phenotype correlation studies show significa Show more
Familial hypertrophic cardiomyopathy (HCM) is attributed to mutations in genes that encode for the sarcomere proteins, especially Mybpc3 and Myh7. Genotype-phenotype correlation studies show significant variability in HCM phenotypes among affected individuals with identical causal mutations. Morphological changes and clinical expression of HCM are the result of interactions with modifier genes. With the exceptions of angiotensin converting enzyme, these modifiers have not been identified. Although mouse models have been used to investigate the genetics of many complex diseases, natural murine models for HCM are still lacking. In this study we show that the DBA/2J (D2) strain of mouse has sequence variants in Mybpc3 and Myh7, relative to widely used C57BL/6J (B6) reference strain and the key features of human HCM. Four-month-old of male D2 mice exhibit hallmarks of HCM including increased heart weight and cardiomyocyte size relative to B6 mice, as well as elevated markers for cardiac hypertrophy including β-myosin heavy chain (MHC), atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and skeletal muscle alpha actin (α1-actin). Furthermore, cardiac interstitial fibrosis, another feature of HCM, is also evident in the D2 strain, and is accompanied by up-regulation of type I collagen and α-smooth muscle actin (SMA)-markers of fibrosis. Of great interest, blood pressure and cardiac function are within the normal range in the D2 strain, demonstrating that cardiac hypertrophy and fibrosis are not secondary to hypertension, myocardial infarction, or heart failure. Because D2 and B6 strains have been used to generate a large family of recombinant inbred strains, the BXD cohort, the D2 model can be effectively exploited for in-depth genetic analysis of HCM susceptibility and modifier screens. 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
Liver X receptor (LXR) isoforms, LXRα and LXRβ, have similar protein structures and ligands, but diverse tissue distribution. We used two synthetic, non-steroidal LXR agonists, T0901317 and GW3965, to Show more
Liver X receptor (LXR) isoforms, LXRα and LXRβ, have similar protein structures and ligands, but diverse tissue distribution. We used two synthetic, non-steroidal LXR agonists, T0901317 and GW3965, to investigate the effects of LXR agonist modulation on prostate specific antigen (PSA) via the expressions of androgen receptors (AR), LXRα, or LXRβ, in prostate carcinoma cells. LXRα- or LXRβ-knockdown cells were transduced with specific shRNA lentiviral particles. LXRα and LXRβ expressions were assessed by immunoblotting and RT-qPCR assays. Cell proliferation was determined by (3) H-thymidine incorporation assays. The effects of LXR agonists and epigallocatechin gallate (EGCG) on PSA expression were determined by ELISA, immunoblotting, or transient gene expression assays. Treatment with either T0901317 or GW3965 significantly attenuated cell proliferation of LNCaP cells. T0901317 treatment suppressed PSA expression while GW3965 treatment enhanced PSA expression. The increase of PSA promoter activity by GW3965 was dependent on the expression of AR. Either LXRα- or LXRβ-knockdown did not affect the activation of androgen on PSA gene expression. However, as compared with mock knockdown-LNCaP cells, the LXRα-knockdown but not the LXRβ-knockdown attenuated the effects of T0901317 and GW3965 on PSA expressions. The effect of GW3965 on PSA expression was blocked by the addition of EGCG. Our results indicate that T0901317 and GW3965 have divergent effects on PSA expressions. The effects of LXR agonists on PSA expression are LXRα-dependent and AR-dependent. EGCG blocks the inducing effect of GW3965 on PSA expression. Show less
Fibroblast growth factor 21 (FGF21) is a novel metabolic regulator. The present study aimed to investigate the effect of FGF21 on cholesterol efflux and the expression of ATP binding cassette (ABC) A1 Show more
Fibroblast growth factor 21 (FGF21) is a novel metabolic regulator. The present study aimed to investigate the effect of FGF21 on cholesterol efflux and the expression of ATP binding cassette (ABC) A1 and G1 in human THP-1 macrophage-derived foam cells. Furthermore, the present study aimed to investigate the role of the liver X receptor (LXR) α in this process. A model of oxidized low-density lipoprotein-induced foam cells from human THP-1 cells was established. The effect of FGF21 on cholesterol efflux was analyzed using a liquid scintillation counter. The expression of ABCA1 and ABCG1 was determined using quantitative polymerase chain reaction and western blot analyses. FGF21 was found to enhance apolipoprotein A1- and high-density lipoprotein-mediated cholesterol efflux. FGF21 was also observed to increase the mRNA and protein expression of ABCA1 and ABCG1. Furthermore, LXRα-short interfering RNA attenuated the stimulatory effects induced by FGF21. These findings suggest that FGF21 may have a protective effect against atherosclerosis by enhancing cholesterol efflux through the induction of LXRα-dependent ABCA1 and ABCG1 expression. 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
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