Jae Young Lee, Shebli Mehrazarin, Abdullah Alshaikh+6 more · 2019 · FASEB journal : official publication of the Federation of American Societies for Experimental Biology · added 2026-04-24
Histone Lys-specific demethylases (KDMs) play a key role in many biological processes through epigenetic mechanisms. However, the role of KDMs in inflammatory responses to oral bacterial infection is Show more
Histone Lys-specific demethylases (KDMs) play a key role in many biological processes through epigenetic mechanisms. However, the role of KDMs in inflammatory responses to oral bacterial infection is poorly understood. Here, we show a novel regulatory role of KDM3C in inflammatory responses to oral bacterial infection. KDM3C expression is transiently suppressed in human and mouse macrophages exposed to LPS from Show less
DHX36 is a DEAH-box helicase that resolves parallel G-quadruplex structures formed in DNA and RNA. The recent co-crystal structure of DHX36 bound G4-DNA revealed an intimate contact, but did not addre Show more
DHX36 is a DEAH-box helicase that resolves parallel G-quadruplex structures formed in DNA and RNA. The recent co-crystal structure of DHX36 bound G4-DNA revealed an intimate contact, but did not address the role of ATP hydrolysis in G4 resolving activity. Here, we demonstrate that unlike on G4-DNA, DHX36 displays ATP-independent unfolding of G4-RNA followed by ATP-dependent refolding, generating a highly asymmetric pattern of activity. Interestingly, DHX36 refolds G4-RNA in several steps, reflecting the discrete steps in forming the G4 structure. We show that the ATP-dependent activity of DHX36 arises from the RNA tail rather than the G4. Mutations that perturb G4 contact result in quick dissociation of the protein from RNA upon ATP hydrolysis, while mutations that interfere with binding the RNA tail induce dysregulated activity. We propose that the ATP-dependent activity of DHX36 may be useful for dynamically resolving various G4-RNA structures in cells. Show less
Anacetrapib is an inhibitor of cholesteryl ester transfer protein (CETP), associated with reduction in LDL cholesterol and increase in HDL cholesterol in hypercholesterolemic patients. Anacetrapib was Show more
Anacetrapib is an inhibitor of cholesteryl ester transfer protein (CETP), associated with reduction in LDL cholesterol and increase in HDL cholesterol in hypercholesterolemic patients. Anacetrapib was not taken forward into filing/registration as a new drug for coronary artery diease, despite the observation of a ∼9% reduction in cardiovascular risk in a large phase III cardiovascular outcomes trial (REVEAL). Anacetrapib displayed no adverse effects throughout extensive preclinical safety evaluation, and no major safety signals were observed in clinical trials studying anacetrapib, including REVEAL. However, anacetrapib demonstrated a long terminal half-life in all species, thought to be due, in part, to distribution into adipose tissue. We sought to understand the dependence of anacetrapib's long half-life on adipose tissue and to explore potential mechanisms that might contribute to the phenomenon. In mice, anacetrapib localized primarily to the lipid droplet of adipocytes in white adipose tissue; in vitro, anacetrapib entry into cultured human adipocytes depended on the presence of a mature adipocyte and lipid droplet but did not require active transport. In vivo, the entry of anacetrapib into adipose tissue did not require lipase activity, as the distribution of anacetrapib into adipose was-not affected by systemic lipase inhibition using poloaxamer-407, a systemic lipase inhibitor. The data from these studies support the notion that the entry of anacetrapib into adipose tissue/lipid droplets does not require active transport, nor does it require mobilization or entry of fat into adipose via lipolysis. Show less
Inactivating mutations of axis inhibition protein 1 (AXIN1), a negative regulator of the Wnt/β-Catenin cascade, are among the common genetic events in human hepatocellular carcinoma (HCC), affecting a Show more
Inactivating mutations of axis inhibition protein 1 (AXIN1), a negative regulator of the Wnt/β-Catenin cascade, are among the common genetic events in human hepatocellular carcinoma (HCC), affecting approximately 10% of cases. In the present manuscript, we sought to define the genetic crosstalk between Axin1 mutants and Wnt/β-catenin as well as Notch signaling cascades along hepatocarcinogenesis. We discovered that c-MET activation and AXIN1 mutations occur concomitantly in ~3%-5% of human HCC samples. Subsequently, we generated a murine HCC model by means of CRISPR/Cas9-based gene deletion of Axin1 (sgAxin1) in combination with transposon-based expression of c-Met in the mouse liver (c-Met/sgAxin1). Global gene expression analysis of mouse normal liver, HCCs induced by c-Met/sgAxin1, and HCCs induced by c-Met/∆N90-β-Catenin revealed activation of the Wnt/β-Catenin and Notch signaling in c-Met/sgAxin1 HCCs. However, only a few of the canonical Wnt/β-Catenin target genes were induced in c-Met/sgAxin1 HCC when compared with corresponding lesions from c-Met/∆N90-β-Catenin mice. To study whether endogenous β-Catenin is required for c-Met/sgAxin1-driven HCC development, we expressed c-Met/sgAxin1 in liver-specific Ctnnb1 null mice, which completely prevented HCC development. Consistently, in AXIN1 mutant or null human HCC cell lines, silencing of β-Catenin strongly inhibited cell proliferation. In striking contrast, blocking the Notch cascade through expression of either the dominant negative form of the recombinant signal-binding protein for immunoglobulin kappa J region (RBP-J) or the ablation of Notch2 did not significantly affect c-Met/sgAxin1-driven hepatocarcinogenesis. Conclusion: We demonstrated here that loss of Axin1 cooperates with c-Met to induce HCC in mice, in a β-Catenin signaling-dependent but Notch cascade-independent way. Show less
Alzheimer's disease (AD) is a chronic neurodegenerative disease that often occurs at a slow pace yet deteriorates with time. MicroRNAs (miRs) have been demonstrated to offer novel therapeutic hope for Show more
Alzheimer's disease (AD) is a chronic neurodegenerative disease that often occurs at a slow pace yet deteriorates with time. MicroRNAs (miRs) have been demonstrated to offer novel therapeutic hope for disease treatment. The aim of the present study was to investigate the effect of miR‑98 on amyloid β (Aβ)‑protein production, oxidative stress and mitochondrial dysfunction through the Notch signaling pathway by targeting hairy and enhancer of split (Hes)‑related with YRPW motif protein 2 (HEY2) in mice with AD. A total of 70 Kunming mice were obtained and subjected to behavioral assessment. The levels of oxidative stress‑related proteins glutathione peroxidase, reduced glutathione, superoxide dismutase, malondialdehyde, acetylcholinesterase and Na+‑K+‑ATP were measured. Morphological changes in brain tissue, HEY2‑positivity levels, neuronal apoptotic index (AI) and neuron mitochondrial DNA (mtDNA) levels were also determined. Subsequently, the levels of miR‑98 and the mRNA and protein levels of HEY2, Jagged1, Notch1, Hes1, Hes5, β‑amyloid precursor protein, B‑cell lymphoma 2 (Bcl‑2) and Bcl‑2‑associated X protein in tissues and hippocampal neurons were determined by reverse transcription‑quantitative polymerase chain reaction and western blot analyses, respectively. Finally, hippocampal neuron viability and apoptosis were determined using an MTT assay and flow cytometry, respectively. The levels of miR‑98‑targeted HEY2 and miR‑98 were low and the levels of HEY2 were high in the AD mice. The AD mice exhibited poorer learning and memory abilities, oxidative stress function, and morphological changes of pyramidal cells in the hippocampal CA1 region. Furthermore, the AD mice exhibited increased protein levels of HEY2 and AI in the CA1 region of brain tissues with reduced mtDNA levels and dysfunctional neuronal mitochondria. miR‑98 suppressed hippocampal neuron apoptosis and promoted hippocampal neuron viability by inactivating the Notch signaling pathway via the inhibition of HEY2. In conclusion, the results demonstrated that miR‑98 reduced the production of Aβ and improved oxidative stress and mitochondrial dysfunction through activation of the Notch signaling pathway by binding to HEY2 in AD mice. Show less
Nutrient excess, a major driver of obesity, diminishes hypothalamic responses to exogenously administered leptin, a critical hormone of energy balance. Here, we aimed to identify a physiological signa Show more
Nutrient excess, a major driver of obesity, diminishes hypothalamic responses to exogenously administered leptin, a critical hormone of energy balance. Here, we aimed to identify a physiological signal that arises from excess caloric intake and negatively controls hypothalamic leptin action. We found that deficiency of the gastric inhibitory polypeptide receptor (Gipr) for the gut-derived incretin hormone GIP protected against diet-induced neural leptin resistance. Furthermore, a centrally administered antibody that neutralizes GIPR had remarkable antiobesity effects in diet-induced obese mice, including reduced body weight and adiposity, and a decreased hypothalamic level of SOCS3, an inhibitor of leptin actions. In contrast, centrally administered GIP diminished hypothalamic sensitivity to leptin and increased hypothalamic levels of Socs3. Finally, we show that GIP increased the active form of the small GTPase Rap1 in the brain and that its activation was required for the central actions of GIP. Altogether, our results identify GIPR/Rap1 signaling in the brain as a molecular pathway linking overnutrition to the control of neural leptin actions. Show less
A history of gestational diabetes mellitus (GDM) has been related to an elevated risk of type 2 diabetes. The melanocortin-4 receptor (MC4R) genotype has been related to glycemic changes in women with Show more
A history of gestational diabetes mellitus (GDM) has been related to an elevated risk of type 2 diabetes. The melanocortin-4 receptor (MC4R) genotype has been related to glycemic changes in women with prior GDM. The objective of this study was to analyze whether lifestyle intervention modified the association between the MC4R genotype and changes in insulin sensitivity among women with prior GDM. We genotyped MC4R rs6567160 and measured glucose and insulin in fasting plasma samples at baseline and during the first 2 follow-up visits in 1128 women with prior GDM. They were randomly assigned to either a 4-y lifestyle intervention involving both diet and physical activity or a control group from a randomized clinical trial, the Tianjin Gestational Diabetes Mellitus Prevention Program. We analyzed the interaction between the MC4R genotype and lifestyle intervention on changes in insulin resistance. From baseline to 1.28 y, the MC4R genotype was related to changes in fasting insulin, HOMA-IR, and homeostasis model assessment of β cell function (HOMA-B) in the intervention group. Each risk allele (C) of rs6567160 was associated with a 0.08-unit greater decrease in log(insulin), log(HOMA-IR), and log(HOMA-B) (P = 0.02, 0.04, and 0.04, respectively), whereas in the control group, each C allele tended to be associated with a greater increase in HOMA-IR (P = 0.09). We found significant interactions between the MC4R genotype and lifestyle intervention on 1.28-y changes in fasting insulin and HOMA-IR (P = 0.006 and 0.008, respectively), and such interaction remained significant when we analyzed the trajectory of changes in insulin and HOMA-IR from baseline to 2.55 y (both P = 0.03). The exploratory results from the first 2 follow-up visits indicate that women with prior GDM carrying a diabetes-increasing MC4R genotype (CC or TC) may obtain better improvement than the TT genotype in insulin resistance through lifestyle intervention. This trial was registered at clinicaltrials.gov as NCT01554358. Show less
Although hundreds of genome-wide association studies-implicated loci have been reported for adult obesity-related traits, less is known about the genetics specific for early-onset obesity and with onl Show more
Although hundreds of genome-wide association studies-implicated loci have been reported for adult obesity-related traits, less is known about the genetics specific for early-onset obesity and with only a few studies conducted in non-European populations to date. Searching for additional genetic variants associated with childhood obesity, we performed a trans-ancestral meta-analysis of 30 studies consisting of up to 13 005 cases (≥95th percentile of body mass index (BMI) achieved 2-18 years old) and 15 599 controls (consistently <50th percentile of BMI) of European, African, North/South American and East Asian ancestry. Suggestive loci were taken forward for replication in a sample of 1888 cases and 4689 controls from seven cohorts of European and North/South American ancestry. In addition to observing 18 previously implicated BMI or obesity loci, for both early and late onset, we uncovered one completely novel locus in this trans-ancestral analysis (nearest gene, METTL15). The variant was nominally associated with only the European subgroup analysis but had a consistent direction of effect in other ethnicities. We then utilized trans-ancestral Bayesian analysis to narrow down the location of the probable causal variant at each genome-wide significant signal. Of all the fine-mapped loci, we were able to narrow down the causative variant at four known loci to fewer than 10 single nucleotide polymorphisms (SNPs) (FAIM2, GNPDA2, MC4R and SEC16B loci). In conclusion, an ethnically diverse setting has enabled us to both identify an additional pediatric obesity locus and further fine-map existing loci. Show less
Micro-RNAs regulate multiple biological behaviors of cancers, making them potential targets of new cancer therapies. MiR-1181 has been demonstrated to perform oncogenic or tumor-suppressing function i Show more
Micro-RNAs regulate multiple biological behaviors of cancers, making them potential targets of new cancer therapies. MiR-1181 has been demonstrated to perform oncogenic or tumor-suppressing function in a tissue-dependent way, but its role in hepatocellular carcinoma (HCC) was unclear. Here, we showed that miR-1181 was significantly overexpressed in HCC tissues when compared with tumor-adjacent normal ones or normal liver tissues from donated organ, and that inhibition of miR-1181 could repress the growth of HCC cells. Through bioinformatics analysis and luciferase reporter assays, we found that axis inhibition protein 1 (AXIN1) was a direct target of miR-1181, and the expression of AXIN1 showed a negative correlation with that of miR-1181 in HCC. Therefore, these data indicated an oncogenic function of miRNA-1181 in the development of HCC and a potential target for the clinical treatment of HCC. Show less
Lead optimization of the diphenylpyridylethanamine (DPPE) and triphenylethanamine (TPE) series of CETP inhibitors to improve their pharmaceutical profile is described. Polar groups at the
Neuropeptide Y (NPY) is the most powerful central neuropeptide implicated in feeding regulation via its receptors. Understanding the role of NPY system is critical to elucidate animal feeding regulati Show more
Neuropeptide Y (NPY) is the most powerful central neuropeptide implicated in feeding regulation via its receptors. Understanding the role of NPY system is critical to elucidate animal feeding regulation. Unlike mammal, the possible mechanisms of NPY system in the food intake of teleost fish are mostly unknown. Therefore, we investigated the regulatory mechanism of NPY and NPY receptors in Siberian sturgeon. In this study, we cloned the cDNA encoding NPY, and assessed the effects of different energy status on npy mRNAs abundance. The expression of npy was decreased in the brain after feeding 1 and 3 h. Besides, the expression of npy was increased after fasting within 15 days, while exhibiting significant decrease after refeeding. In order to further characterize the role of NPY receptor in fish, we performed acute intraperitoneal (i.p.) injection of NPY Y1 and Y2 receptor agonists, which is [Leu 31, Pro 34] NPY and NPY13-36 respectively. The results showed that the food intake of Siberian sturgeon was increased within 30 mins after injection of both Y1 and Y2 receptor agonist. To explore the relationship between NPY, NPY receptors and another appetite peptides, we examined the level of npy, cocaine- and amphetamine-regulated transcript (cart) and melanocortin-4 receptor (mc4r) by injected Y1 and Y2 receptor agonist. The results suggested that cart expression was regulated by NPY which acts on Y1 receptor or Y2 receptor. While mc4r expression just was mediated by NPY and Y1 receptor. Show less
Epigenetic alternation is a common contributing factor to neoplastic transformation. Although previous studies have reported a cluster of aberrant promoter methylation changes associated with silencin Show more
Epigenetic alternation is a common contributing factor to neoplastic transformation. Although previous studies have reported a cluster of aberrant promoter methylation changes associated with silencing of tumor suppressor genes, little is known concerning their sequential DNA methylation changes during the carcinogenetic process. The aim of the present study was to address a genome-wide search for identifying potentially important methylated changes and investigate the onset and pattern of methylation changes during the progression of colorectal neoplasia. A three-phase design was employed in this study. In the screening phase, DNA methylation profile of 12 pairs of colorectal cancer (CRC) and adjacent normal tissues was analyzed by using the Illumina MethylationEPIC BeadChip. Significant CpG sites were selected based on a cross-validation analysis from The Cancer Genome Atlas (TCGA) database. Methylation levels of candidate CpGs were assessed using pyrosequencing in the training dataset (tumor lesions and adjacent normal tissues from 46 CRCs) and the validation dataset (tumor lesions and paired normal tissues from 13 hyperplastic polyps, 129 adenomas, and 256 CRCs). A linear mixed-effects model was used to examine the incremental changes of DNA methylation during the progression of colorectal neoplasia. The comparisons between normal and tumor samples in the screening phase revealed an extensive CRC-specific methylomic pattern with 174,006 (21%) methylated CpG sites, of which 22,232 (13%) were hyermethylated and 151,774 (87%) were hypomethylated. Hypermethylation mostly occurred in CpG islands with an overlap of gene promoters, while hypomethylation tended to be mapped far away from functional regions. Further cross validation analysis from TCGA dataset confirmed 265 hypermethylated promoters coupling with downregulated gene expression. Among which, hypermethylated changes in MEEPD2 promoter was successfully replicated in both training and validation phase. Significant hypermethylation appeared since precursor lesions with an extensive modification in CRCs. The linear mixed-effects modeling analysis found that a cumulative pattern of MPPED2 methylation changes from normal mucosa to hyperplastic polyp to adenoma, and to carcinoma (P < 0.001). Our findings indicate that epigenetic alterations of MPPED2 promoter region appear sequentially during the colorectal neoplastic progression. It might be able to serve as a promising biomarker for early diagnosis and stage surveillance of colorectal tumorigenesis. Show less
Growth and fat deposition are important economic traits due to the influence on production in pigs. In this study, a dataset of 1200 pigs with 345,570 SNPs genotyped by sequencing (GBS) was used to co Show more
Growth and fat deposition are important economic traits due to the influence on production in pigs. In this study, a dataset of 1200 pigs with 345,570 SNPs genotyped by sequencing (GBS) was used to conduct a GWAS with single-marker regression method to identify SNPs associated with body weight and backfat thickness (BFT) and to search for candidate genes in Landrace and Yorkshire pigs. A total of 27 and 13 significant SNPs were associated with body weight and BFT, respectively. In the region of 149.85-149.89 Mb on SSC6, the SNP (SSC6: 149876737) for body weight and the SNP (SSC6: 149876507) for BFT were in the same locus region (a gap of 230 bp). Two SNPs were located in the DOCK7 gene, which is a protein-coding gene that plays an important role in pigmentation. Two SNPs located on SSC8: 54567459 and SSC11: 33043081 were found to overlap weight and BFT; however, no candidate gene was found in these regions. In addition, based on other significant SNPs, two positional candidate genes, NSRP1 and CADPS, were proposed to influence weight. In conclusion, this is the first study report using GBS data to identify the significant SNPs for weight and BFT. A total of four particularly interesting SNPs and one potential candidate genes (DOCK7) were found for these traits in domestic pigs. This study improves our knowledge to better understand the complex genetic architecture of weight and BFT, but further validation studies of these candidate loci and genes are recommended in pigs. Show less
The therapeutic strategies for advanced gastric cancer (GC) remain unsatisfying and limited. Therefore, it is still imperative to fully elucidate the mechanisms underlying GC aggressive progression. T Show more
The therapeutic strategies for advanced gastric cancer (GC) remain unsatisfying and limited. Therefore, it is still imperative to fully elucidate the mechanisms underlying GC aggressive progression. The prognostic value and biological functions of low density lipoprotein receptor class A domain containing protein 2 (LDLRAD2) in GC have never been studied yet. We found that LDLRAD2 expression was significantly upregulated in GC and closely correlated with poor prognosis in GC patients. Functionally, LDLRAD2 promoted epithelial-mesenchymal transition, migration and invasion, and metastasis of GC cells. Mechanistically, LDLRAD2 interacted with and inhibited Axin1 from binding to cytoplasmic β-catenin, which facilitated the nuclear translocation of β-catenin, thereby activating Wnt/β-catenin pathway. Inhibition of β-catenin activity markedly abolished LDLRAD2-induced migration, invasion and metastasis. Together, these results suggested that LDLRAD2 contributed to invasion and metastasis of GC through activating Wnt/β-catenin pathway. LDLRAD2/ Wnt/β-catenin axis may be a potential therapeutic target for GC treatment. Show less
The melanocortin system is a brain circuit that influences energy balance by regulating energy intake and expenditure. In addition, the brain-melanocortin system controls adipose tissue metabolism to Show more
The melanocortin system is a brain circuit that influences energy balance by regulating energy intake and expenditure. In addition, the brain-melanocortin system controls adipose tissue metabolism to optimize fuel mobilization and storage. Specifically, increased brain-melanocortin signaling or negative energy balance promotes lipid mobilization by increasing sympathetic nervous system input to adipose tissue. In contrast, calorie-independent mechanisms favoring energy storage are less understood. Here, we demonstrate that reduction of brain-melanocortin signaling actively promotes fat mass gain by activating the lipogenic program and adipocyte and endothelial cell proliferation in white fat depots independently of caloric intake via efferent nerve fibers conveyed by the common hepatic branch of the vagus nerve. Those vagally regulated obesogenic signals also contribute to the fat mass gain following chronic high-fat diet feeding. These data reveal a physiological mechanism whereby the brain controls energy stores that may contribute to increased susceptibility to obesity. Show less
Cell division cycle 20 (CDC20) is frequently overexpressed in malignant tumours and involved in the differentiation process of hematopoietic stem cells. However, the role of CDC20 in prostate cancer s Show more
Cell division cycle 20 (CDC20) is frequently overexpressed in malignant tumours and involved in the differentiation process of hematopoietic stem cells. However, the role of CDC20 in prostate cancer stem-like cells (CSCs) remains poorly understood. The expression of CDC20, CD44, β-catenin were examined in prostate cancer specimens by immunohistochemistry assay, the role of CDC20 on the stem-like properties of prostate CSCs was accessed by real-time quantitive PCR, spheroid formation, in vitro and in vivo limiting dilution assay. CDC20 was associated with malignant progression of prostate cancer, the patients with both high expression CDC20 and CD44 or β-catenin were associated with more aggressive clinicopathological features and poor prognosis. CDC20 was usually enriched in CD44 Our results indicated that CDC20 maintains the self-renewal ability of CD44 Show less
Family with sequence similarity 83, member A (FAM83A), as a potential tumor promoter, was reported to contribute to the progression of several malignant tumors. However, the significance of FAM83A in Show more
Family with sequence similarity 83, member A (FAM83A), as a potential tumor promoter, was reported to contribute to the progression of several malignant tumors. However, the significance of FAM83A in invasion and metastasis of non-small cell lung cancer (NSCLC) remains largely unknown. In this study, we found that FAM83A expression was significantly increased in NSCLC tissues. High expression of FAM83A was positively associated with tumor metastasis and poor survival of NSCLC patients. Functional experiments revealed that FAM83A knockdown could suppress NSCLC cell migration and invasion both Show less
Diabetic nephropathy (DN) is one of the major diabetic complications that lead to end-stage renal failure. Angiopoietin-like protein-4 (ANGPTL-4) has been reported to be dysregulated in diabetes melli Show more
Diabetic nephropathy (DN) is one of the major diabetic complications that lead to end-stage renal failure. Angiopoietin-like protein-4 (ANGPTL-4) has been reported to be dysregulated in diabetes mellitus and diabetic complications. However, the role of ANGPTL-4 in glomerular mesangial cells (MCs) during DN remains unclear. In the present study, we evaluated the role of ANGPTL-4 in MCs in response to high glucose (HG) condition and the potential mechanism. The results proved that ANGPTL-4 expression is significantly increased in HG-stimulated MCs. Knockdown of ANGPTL-4 suppressed HG-induced cell proliferation of MCs. The production of pro-inflammatory cytokines including TNF-α, IL-1β, IL-6 were decreased in ANGPTL-4 knocked down MCs. Inhibition of ANGPTL-4 markedly suppressed the expressions of extracellular matrix (ECM) proteins, collagen IV (Col IV) and fibronectin (FN), in HG-stimulated MCs. Furthermore, ANGPTL-4 knockdown inhibited the HG-induced activation of NF-κB signaling pathway in MCs. Collectively, knockdown of ANGPTL-4 suppressed HG-induced cell proliferation, inflammatory response, and ECM accumulation inhibiting NF-κB signaling pathway in MCs. These findings suggested that ANGPTL-4 might be a therapeutic target for the prevention and treatment of DN. Show less
Billions of people have obesity-related metabolic syndromes such as diabetes and hyperlipidemia. Promoting the browning of white adipose tissue has been suggested as a potential strategy, but a drug s Show more
Billions of people have obesity-related metabolic syndromes such as diabetes and hyperlipidemia. Promoting the browning of white adipose tissue has been suggested as a potential strategy, but a drug still needs to be identified. Here, genetic deletion of activating transcription factor 3 ( Show less
Mitogen-activated protein kinases (MAPKs) are key regulators of signal transduction and cell responses. Abnormalities in MAPKs are associated with multiple diseases. Dual-specificity phosphatases (DUS Show more
Mitogen-activated protein kinases (MAPKs) are key regulators of signal transduction and cell responses. Abnormalities in MAPKs are associated with multiple diseases. Dual-specificity phosphatases (DUSPs) dephosphorylate many key signaling molecules, including MAPKs, leading to the regulation of duration, magnitude, or spatiotemporal profiles of MAPK activities. Hence, DUSPs need to be properly controlled. Protein post-translational modifications, such as ubiquitination, phosphorylation, methylation, and acetylation, play important roles in the regulation of protein stability and activity. Ubiquitination is critical for controlling protein degradation, activation, and interaction. For DUSPs, ubiquitination induces degradation of eight DUSPs, namely, DUSP1, DUSP4, DUSP5, DUSP6, DUSP7, DUSP8, DUSP9, and DUSP16. In addition, protein stability of DUSP2 and DUSP10 is enhanced by phosphorylation. Methylation-induced ubiquitination of DUSP14 stimulates its phosphatase activity. In this review, we summarize the knowledge of the regulation of DUSP stability and ubiquitination through post-translational modifications. Show less
Persistent pulmonary hypertension of the newborn (PPHN) is a severe clinical problem among neonatal intensive care unit (NICU) patients. The genetic pathogenesis of PPHN is unclear. Only a few genetic Show more
Persistent pulmonary hypertension of the newborn (PPHN) is a severe clinical problem among neonatal intensive care unit (NICU) patients. The genetic pathogenesis of PPHN is unclear. Only a few genetic polymorphisms have been identified in infants with PPHN. Our study aimed to investigate the potential genetic etiology of PPHN. This study recruited PPHN patients admitted to the NICU of the Children's Hospital of Fudan University from Jan 2016 to Dec 2017. Exome sequencing was performed for all patients. Variants in reported PPHN/pulmonary arterial hypertension (PAH)-related genes were assessed. Single nucleotide polymorphism (SNP) association and gene-level analyses were carried out in 74 PPHN cases and 115 non-PPHN controls with matched baseline characteristics. Among the patient cohort, 74 (64.3%) patients were late preterm and term infants (≥ 34 weeks gestation) and 41 (35.7%) were preterm infants (< 34 weeks gestation). Preterm infants with PPHN exhibited low birth weight and a high frequency of bronchopulmonary dysplasia, respiratory distress syndrome (RDS) and mortality. Nine patients (only one preterm infant) were identified as harboring genetic variants, including three with pathogenic/likely pathogenic variants in TBX4 and BMPR2 and six with variants of unknown significance in BMPR2, SMAD9, TGFB1, KCNA5 and TRPC6. Three SNPs (rs192759073, rs1047883 and rs2229589) in CPS1 and one SNP (rs1044008) in NOTCH3 were significantly associated with PPHN (p < 0.05). CPS1 and SMAD9 were identified as risk genes for PPHN (p < 0.05). In this study, we identified genetic variants in PPHN patients, and we reported CPS1, NOTCH3 and SMAD9 as risk genes for late preterm and term PPHN in a single-center Chinese cohort. Our findings provide additional genetic evidence of the pathogenesis of PPHN and new insight into potential strategies for disease treatment. Show less
Cholesteryl ester transfer protein (CETP) plays an important role in lipid metabolism. Low levels of high-density lipoprotein cholesterol (HDL-C) increase the risk of type 2 diabetes (T2D). This study Show more
Cholesteryl ester transfer protein (CETP) plays an important role in lipid metabolism. Low levels of high-density lipoprotein cholesterol (HDL-C) increase the risk of type 2 diabetes (T2D). This study investigated CETP gene variants to assess the risk of T2D and specific complications of diabetic kidney disease (DKD) and diabetic retinopathy. Towards this, a total of 3023 Taiwanese individuals (1383 without T2D, 1640 with T2D) were enrolled in this study. T2D mice (+Lepr Show less
Neuromuscular junction is a synapse between motoneurons and skeletal muscles, where acetylcholine receptors (AChRs) are concentrated to control muscle contraction. Studies of this synapse have contrib Show more
Neuromuscular junction is a synapse between motoneurons and skeletal muscles, where acetylcholine receptors (AChRs) are concentrated to control muscle contraction. Studies of this synapse have contributed to our understanding of synapse assembly and pathological mechanisms of neuromuscular disorders. Nevertheless, underlying mechanisms of NMJ formation was not well understood. To this end, we took a novel approach - studying mutant genes implicated in congenital myasthenic syndrome (CMS). We showed that knock-in mice carrying N88K, a prevalent CMS mutation of Rapsyn (Rapsn), died soon after birth with profound NMJ deficits. Rapsn is an adapter protein that bridges AChRs to the cytoskeleton and possesses E3 ligase activity. In investigating how N88K impairs the NMJ, we uncovered a novel signaling pathway by which Agrin-LRP4-MuSK induces tyrosine phosphorylation of Rapsn, which is required for its self-association and E3 ligase activity. Our results also provide insight into pathological mechanisms of CMS. Show less
Metastasis is the major cause of treatment failure in patients with cancer. Hinokitiol, a metal chelator derived from natural plants, has anti-inflammatory and antioxidant activities as well as antica Show more
Metastasis is the major cause of treatment failure in patients with cancer. Hinokitiol, a metal chelator derived from natural plants, has anti-inflammatory and antioxidant activities as well as anticancer effects. We investigated the potential anticancer effects of hinokitiol in metastatic melanoma cell line B16-F10. Exposure of the melanoma B16-F10 cells to hinokitiol significantly inhibited colony formation and cell viability in a time and concentration-dependent manner. The hinokitiol-treated cells exhibited apoptotic features in morphological assay. Results from Western blot and immunoprecipitation showed that hinokitiol treatment decreased survivin protein levels and increased suvivin ubiquitination. Pretreatment with proteosome inhibitors effectively prevented hinokitiol-induced decrease in survivin expression, implying that ubiquitin/proteosome pathway involved in hinokitiol-reduced survivin expression. Hinokitiol rapidly induced ERK phosphorylation followed by a sustained dephosphorylation, which accompanied with an increase in expression of tumor suppressor MKP-3 (mitogen-activated protein kinase phosphatase-3). Inhibition of hinokitiol-induced ERK activation by MEK inhibitor U0126 completely blocked expression of MKP-3. More importantly, inhibition of MKP-3 activity by NSC 95397 significantly inhibited hinokitiol-induced ERK dephosphorylation, ubiquitination and downregulation of survivin. These results suggested that hinokitiol inhibited growth of B16-F10 melanoma through downregulation of survivin by activating ERK/MKP-3/proteosome pathway. Hinokitiol-inhibition of survivin may be a novel and potential approach for melanoma therapy. Hinokitiol can be useful for developing therapeutic agent for melanoma. Show less
Rosa rugosa Thunb. is a traditional Chinese medicine that was used in the treatment of cardiovascular diseases and relative risk factors such as diabetes, hyperlipidemia, hypertension, and inflammatio Show more
Rosa rugosa Thunb. is a traditional Chinese medicine that was used in the treatment of cardiovascular diseases and relative risk factors such as diabetes, hyperlipidemia, hypertension, and inflammation. Rosa rugosa flavonoids (RRFs) are the main components in Rosa rugosa Thunb. Several studies have demonstrated that RRFs can regulate plasma lipid contents, but the related mechanism of which has not yet been elucidated clearly. The goal of this study was to clarify the effects of RRFs on triglyceride metabolism and its related mechanisms. RRFs were obtained by ethanol extraction from Rosa rugosa Thunb.. Transgenic mice expressing human Apolipoprotein C3 (ApoC3) were used as a mouse model of hypertriglyceridemia. Fenofibrate (FNB), a PPARα agonist, was used as a positive control drug of decreasing high triglyceride. FNB (100 mg/kg) or RRFs (300 mg/kg) were given to the mice by gavage daily. Two weeks later, the changes of plasma lipid levels in the mice were measured by commercial kits, the clearance of triglyceride was evaluated by oral fat load test, and expression of the genes related to lipid β-oxidation and synthesis was detected in the mice livers by real time PCR. RRFs, as well as FNB, were found to significantly reduce plasma triglyceride (TG) levels in ApoC3 transgenic mice after administration of the drug for two weeks. Plasma lipid clearance rate was increased and lipid content in the mice livers was reduced after administration of RRF. Treatment with RRFs up-regulated mRNA expression of PPARα and its downstream gene of ACOX, while down-regulated mRNA expression of the genes related to fatty acid synthesis (FASN, SREBP-1c, and ACC1). The expression of LPL was raised, while the expression of ApoC3 was decreased, and Foxo1 was inhibited by RRFs in the mice livers. RRFs can reduce plasma TG levels by repressing the expression of ApoC3 and inducing the expression of LPL in liver. RRFs could also reduce triglyceride in hepatocytes through increasing β-oxidation and decreasing synthesis of the lipids. These findings show the potency of further clinical application of RRFs as a hypolipidemic drug for treatment of cardiovascular diseases. Show less
Further analysis has revealed that the signal reported in Extended Data Fig. 1c of this Letter is attributed to phosphorylethanolamine, not carbamoyl phosphate. A newly developed derivatization method Show more
Further analysis has revealed that the signal reported in Extended Data Fig. 1c of this Letter is attributed to phosphorylethanolamine, not carbamoyl phosphate. A newly developed derivatization method revealed that the level of carbamoyl phosphate in these NSCLC extracts is below the detection threshold of approximately 10 nanomoles. These findings do not alter the overall conclusions of the Letter; see associated Amendment for full details. The Letter has not been corrected online. Show less
Long noncoding RNA CPS1-IT1 is recently recognized as a tumor suppressor in several cancers. Here, we investigate the role of CPS1-IT1 in human melanoma. Presently, our study reveals the low expressio Show more
Long noncoding RNA CPS1-IT1 is recently recognized as a tumor suppressor in several cancers. Here, we investigate the role of CPS1-IT1 in human melanoma. Presently, our study reveals the low expression of CPS1-IT1 in human melanoma tissues and cell lines, which is significantly associated with metastasis and tumor stage. Besides, the potential of CPS1-IT1 as a prognosis-predictor is strongly indicated. Functionally, CPS1-IT1 overexpression inhibits cell migration, invasion, epithelial-mesenchymal transition, and angiogenesis in melanoma cells. CYR61, an angiogenic factor that participates in tumor metastasis as well as a recognized oncogene in melanoma, is shown to be confined under CPS1-IT1 overexpression in melanoma cells. Furthermore, enforced expression of Cyr61 in CPS1-IT1-silenced melanoma cells dramatically normalized the protein level of Cyr61 and that of its downstream targets vascular endothelial growth factor and matrix metalloproteinase-9, as well as the repressive effect of CPS1-IT1 overexpression on melanoma cell metastasis. BRG1, a core component of SWI/SNF complex, is implied to interact with both CPS1-IT1 and Cyr61 in melanoma cells. Moreover, CPS1-IT1 negatively regulates Cyr61 expression by blocking the binding of BRG1 to Cyr61 promoter. Jointly, CPS1-IT1 controls melanoma metastasis through impairing Cyr61 expression via competitively binding with BRG1, uncovering a novel potential therapeutic and prognostic biomarker for patients with melanoma. Show less
Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) in combination with CRISPR/Cas9 genome editing provide unparalleled opportunities to study cardiac biology and disease. However, Show more
Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) in combination with CRISPR/Cas9 genome editing provide unparalleled opportunities to study cardiac biology and disease. However, sarcomeres, the fundamental units of myocyte contraction, are immature and nonlinear in hiPSC-CMs, which technically challenge accurate functional interrogation of contractile parameters in beating cells. Furthermore, existing analysis methods are relatively low-throughput, indirectly assess contractility, or only assess well-aligned sarcomeres found in mature cardiac tissues. We aimed to develop an analysis platform that directly, rapidly, and automatically tracks sarcomeres in beating cardiomyocytes. The platform should assess sarcomere content, contraction and relaxation parameters, and beat rate. We developed SarcTrack, a MatLab software that monitors fluorescently tagged sarcomeres in hiPSC-CMs. The algorithm determines sarcomere content, sarcomere length, and returns rates of sarcomere contraction and relaxation. By rapid measurement of hundreds of sarcomeres in each hiPSC-CM, SarcTrack provides large data sets for robust statistical analyses of multiple contractile parameters. We validated SarcTrack by analyzing drug-treated hiPSC-CMs, confirming the contractility effects of compounds that directly activate (CK-1827452) or inhibit (MYK-461) myosin molecules or indirectly alter contractility (verapamil and propranolol). SarcTrack analysis of hiPSC-CMs carrying a heterozygous truncation variant in the myosin-binding protein C ( MYBPC3) gene, which causes hypertrophic cardiomyopathy, recapitulated seminal disease phenotypes including cardiac hypercontractility and diminished relaxation, abnormalities that normalized with MYK-461 treatment. SarcTrack provides a direct and efficient method to quantitatively assess sarcomere function. By improving existing contractility analysis methods and overcoming technical challenges associated with functional evaluation of hiPSC-CMs, SarcTrack enhances translational prospects for sarcomere-regulating therapeutics and accelerates interrogation of human cardiac genetic variants. Show less