Contribution of dipeptidyl peptidase 10 to airway dysfunction in patients with NSAID-exacerbated respiratory disease.

BACKGROUND: Genetic variants of dipeptidyl peptidase 10 (DPP10) have been suggested to contribute to the development of NSAID-exacerbated respiratory disease (NERD). However, the mechanisms of how DPP10 contributes to NERD phenotypes remain unclear. OBJECTIVE: To demonstrate the exact role of DPP10 in the pathogenesis of NERD. METHODS: Patients with NERD (n = 110), those with aspirin-tolerant asthma (ATA, n = 130) and healthy control subjects (HCs, n = 80) were enrolled. Clinical characteristics were analysed according to the serum DPP10 levels in both NERD and ATA groups. The function of DPP10 in airway inflammation and remodelling was investigated with in vitro, ex vivo and in vivo experiments. RESULTS: NERD patients had higher levels of serum DPP10 and TGF-ß1 with lower FEV1 than ATA patients or HCs (p < .05 for each). NERD patients with higher DPP10 levels had higher TGF-ß1, but lower FEV1 (p < .05 for all), whilst no differences were noted in ATA patients. Moreover, the seum DPP10 levels had a positive correlation with TGF-ß1 (r = 0.384, p < .001), but a negative correlation with FEV1 (r = -0.230, p = .016) in NERD patients. In in vitro studies, expression of DPP10 in airway epithelial cells was enhanced by TGF-ß1 treatments. Furthermore, DPP10 was found to be produced from immune cells and this molecule induced the ERK phosphorylation in airway epithelial cells, which was suppressed by anti-DPP10 treatment. In asthmatic mouse models, increased levels of DPP10 in the serum and TGF-ß1 in the bronchoalveolar lavage fluid were noted, which were suppressed by anti-DPP10 treatment. Moreover, anti-DPP10 treatment inhibited the ERK phosphorylation and extracellular matrix deposition in the lungs. CONCLUSIONS AND CLINICAL RELEVANCE: These findings suggest that increased production of DPP10 may contribute to TGF-ß1-mediated airway dysfunction in NERD patients, where blockade of DPP10 may have potential benefits.

Fine-mapping scan of bipolar disorder susceptibility loci in Latino pedigrees.

We previously identified bipolar disorder (BD) susceptibility loci on 8q24, 14q32, and 2q12-14 in a genome-wide nonparametric linkage screen in a Latino cohort. We now perform a fine mapping analysis using a dense map of additional SNPs to identify BD susceptibility genes within these regions. One thousand nine hundred and thirty-eight individuals with Latino ancestry (880 individuals with BD Type I or Schizoaffective, Bipolar Type) from 416 Latino pedigrees from the United States, Mexico, Costa Rica, and Guatemala were genotyped with 3,074 SNPs to provide dense coverage of the 8q24 (11.5 cM), 14q32 (7.5 cM), and 2q12-14 (6.5 cM) chromosomal loci. Single-marker association tests in the presence of linkage were performed using the LAMP software. The top linkage peak (rs7834818; LOD = 5.08, p = 3.30E - 5) and associated single marker (rs2280915, p = 2.70E - 12) were located within FBXO32 on 8q24. On chromosome 2, the top linkage peak (rs6750326; LOD = 5.06, p = 3.50E - 5) and associated single marker (rs11887088, p = 2.90E - 6) were located in intragenic regions near ACTR3 and DPP10. None of the additional markers in the region around chromosome 14q32 met significance levels for linkage or association. We identified six SNPs on 2q12-q14 and one SNP in FBXO32 on 8q24 that were significantly associated with BD in this Latino cohort.

K+ Channel Modulatory Subunits KChIP and DPP Participate in Kv4-Mediated Mechanical Pain Control.

The K+ channel pore-forming subunit Kv4.3 is expressed in a subset of nonpeptidergic nociceptors within the dorsal root ganglion (DRG), and knockdown of Kv4.3 selectively induces mechanical hypersensitivity, a major symptom of neuropathic pain. K+ channel modulatory subunits KChIP1, KChIP2, and DPP10 are coexpressed in Kv4.3+ DRG neurons, but whether they participate in Kv4.3-mediated pain control is unknown. Here, we show the existence of a Kv4.3/KChIP1/KChIP2/DPP10 complex (abbreviated as the Kv4 complex) in the endoplasmic reticulum and cell surface of DRG neurons. After intrathecal injection of a gene-specific antisense oligodeoxynucleotide to knock down the expression of each component in the Kv4 complex, mechanical hypersensitivity develops in the hindlimbs of rats in parallel with a reduction in all components in the lumbar DRGs. Electrophysiological data further indicate that the excitability of nonpeptidergic nociceptors is enhanced. The expression of all Kv4 complex components in DRG neurons is downregulated following spinal nerve ligation (SNL). To rescue Kv4 complex downregulation, cDNA constructs encoding Kv4.3, KChIP1, and DPP10 were transfected into the injured DRGs (defined as DRGs with injured spinal nerves) of living SNL rats. SNL-evoked mechanical hypersensitivity was attenuated, accompanied by a partial recovery of Kv4.3, KChIP1, and DPP10 surface levels in the injured DRGs. By showing an interdependent regulation among components in the Kv4 complex, this study demonstrates that K+ channel modulatory subunits KChIP1, KChIP2, and DPP10 participate in Kv4.3-mediated mechanical pain control. Thus, these modulatory subunits could be potential drug targets for neuropathic pain.SIGNIFICANCE STATEMENT Neuropathic pain, a type of moderate to severe chronic pain resulting from nerve injury or disorder, affects 6.9%-10% of the global population. However, less than half of patients report satisfactory pain relief from current treatments. K+ channels, which act to reduce nociceptor activity, have been suggested to be novel drug targets for neuropathic pain. This study is the first to show that K+ channel modulatory subunits KChIP1, KChIP2, and DPP10 are potential drug targets for neuropathic pain because they form a channel complex with the K+ channel pore-forming subunit Kv4.3 in a subset of nociceptors to selectively inhibit mechanical hypersensitivity, a major symptom of neuropathic pain.

LncRNA DPP10-AS1 promotes malignant processes through epigenetically activating its cognate gene DPP10 and predicts poor prognosis in lung cancer patients.

OBJECTIVE: The purpose of this study was to explore the function and gene expression regulation of the newly identified lncRNA DPP10-AS1 in lung cancer, and its potential value as a prognostic biomarker. METHODS: qRT-PCR and Western blot were conducted to detect the expression of DDP10-AS1 and DPP10 in lung cancer cell lines and tissues. The effects of DDP10-AS1 on DPP10 expression, cell growth, invasion, apoptosis, and in vivo tumor growth were investigated in lung cancer cells by Western blot, rescue experiments, colony formation, flow cytometry, and xenograft animal experiments. RESULTS: The novel antisense lncRNA DPP10-AS1 was found to be highly expressed in cancer tissues (P < 0.0001), and its upregulation predicted poor prognosis in patients with lung cancer (P = 0.0025). Notably, DPP10-AS1 promoted lung cancer cell growth, colony formation, and cell cycle progression, and repressed apoptosis in lung cancer cells by upregulating DPP10 expression. Additionally, DPP10-AS1 facilitated lung tumor growth via upregulation of DPP10 protein in a xenograft mouse model. Importantly, DPP10-AS1 positively regulated DPP10 gene expression, and both were coordinately upregulated in lung cancer tissues. Mechanically, DPP10-AS1 was found to associate with DPP10 mRNA but did not enhance DPP10 mRNA stability. Hypomethylation of DPP10-AS1 and DPP10 contributed to their coordinate upregulation in lung cancer. CONCLUSIONS: These findings indicated that the upregulation of the antisense lncRNA DPP10-AS1 promotes lung cancer malignant processes and facilitates tumorigenesis by epigenetically regulating its cognate sense gene DPP10. DPP10-AS1 may serve as a candidate prognostic biomarker and a potential therapeutic target in lung cancer.

Long non-coding RNA DPP10-AS1 exerts anti-tumor effects on colon cancer via the upregulation of ADCY1 by regulating microRNA-127-3p.

Herein we hypothesized that DPP10-AS1 could affect the development of colon cancer via the interaction with miR-127-3p and adenylate cyclase 1 (ADCY1). After sorting of CD133 positive cells, sphere formation, colony formation, proliferation, invasion, migration, and apoptosis were detected to explore the involvement of DPP10-AS1 and miR-127-3p in the colon cancer stem cell (CCSC) properties through gain- and loss-of function approaches. Furthermore, tumor xenograft in nude mice was conducted to investigate the effect of DPP10-AS1 and miR-127-3p on tumor growth in vivo. Poorly expressed DPP10-AS1 and ADCY1, while highly expressed miR-127-3p were found in CCSCs. Low expression of DPP10-AS1 was correlated with TNM stage, lymphatic node metastasis, and tumor differentiation. Upregulation of DPP10-AS1 increased ADCY1 protein expression, decreased the protein expression of CCSC-related factors, inhibited sphere formation, colony formation, proliferation, invasion and migration, and accelerated apoptosis of HT-29 and SW480 cells by suppressing the expression of miR-127-3p. Further, the above in vitro findings were also confirmed by in vivo assays. Taken together, this study demonstrates that DPP10-AS1 inhibits CCSC proliferation by regulating miR-127-3p and ADCY1, providing fresh insight into a promising novel treatment strategy for colon cancer.

Tetramethylpyrazine reduces prostate cancer malignancy through inactivation of the DPP10­AS1/CBP/FOXM1 signaling pathway.

Tetramethylpyrazine (TMP), a Chinese herbal medicine, has been reported to possess anticancer effects. Emerging evidence suggests that various long noncoding RNAs (lncRNAs) serve important roles in cancer initiation and progression. In the present study, the tumor­suppressive effects of TMP in human PCa cells was examined and the underlying mechanisms of its actions were determined. The data showed that TMP treatment reduced cell viability and increased apoptosis in a dose­dependent manner. Reverse transcription­quantitative PCR showed TMP treatment increased the expression of lncRNA DPP10­AS1 in PCa cells. Furthermore, DPP10­AS1 was also upregulated in TMP­resistant PCa cells. Knockdown of DPP10­AS1 reversed TMP resistance, whereas increased expression of DPP10­AS1 abrogated the TMP­mediated cytotoxicity in PCa cells. In addition, forkhead box M1 (FOXM1) was verified as the functional target of DPP10­AS1, and knockdown of FOXM1 reversed the TMP/DPP10­AS1­induced cell cytotoxicity. Mechanistically, DPP10­AS1 was associated with CREB binding protein, thereby induced H3K27ac enrichment at the promoter region of the FOXM1 gene. In conclusion, the present study showed that TMP may be a promising treatment agent for PCa and lncRNA DPP10­AS1 may be a promising therapeutic target for TMP treatment.

Transcriptome analysis of neural progenitor cells derived from Lowe syndrome induced pluripotent stem cells: identification of candidate genes for the neurodevelopmental and eye manifestations.

BACKGROUND: Lowe syndrome (LS) is caused by loss-of-function mutations in the X-linked gene OCRL, which codes for an inositol polyphosphate 5-phosphatase that plays a key role in endosome recycling, clathrin-coated pit formation, and actin polymerization. It is characterized by congenital cataracts, intellectual and developmental disability, and renal proximal tubular dysfunction. Patients are also at high risk for developing glaucoma and seizures. We recently developed induced pluripotent stem cell (iPSC) lines from three patients with LS who have hypomorphic variants affecting the 3' end of the gene, and their neurotypical brothers to serve as controls. METHODS: In this study, we used RNA sequencing (RNA-seq) to obtain transcriptome profiles in LS and control neural progenitor cells (NPCs). RESULTS: In a comparison of the patient and control NPCs (n = 3), we found 16 differentially expressed genes (DEGs) at the multiple test adjusted p value (padj) < 0.1, with nine at padj < 0.05. Using nominal p value < 0.05, 319 DEGs were detected. The relatively small number of DEGs could be due to the fact that OCRL is not a transcription factor per se, although it could have secondary effects on gene expression through several different mechanisms. Although the number of DEGs passing multiple test correction was small, those that were found are quite consistent with some of the known molecular effects of OCRL protein, and the clinical manifestations of LS. Furthermore, using gene set enrichment analysis (GSEA), we found that genes increased expression in the patient NPCs showed enrichments of several gene ontology (GO) terms (false discovery rate < 0.25): telencephalon development, pallium development, NPC proliferation, and cortex development, which are consistent with a condition characterized by intellectual disabilities and psychiatric manifestations. In addition, a significant enrichment among the nominal DEGs for genes implicated in autism spectrum disorder (ASD) was found (e.g., AFF2, DNER, DPP6, DPP10, RELN, CACNA1C), as well as several that are strong candidate genes for the development of eye problems found in LS, including glaucoma. The most notable example is EFEMP1, a well-known candidate gene for glaucoma and other eye pathologies. CONCLUSION: Overall, the RNA-seq findings present several candidate genes that could help explain the underlying basis for the neurodevelopmental and eye problems seen in boys with LS.

DPP10 is a new regulator of Nav1.5 channels in human heart.

BACKGROUND: Cardiac accessory ß-subunits are part of macromolecular Nav1.5 channel complexes modulating biophysical properties and contributing to arrhythmias. Recent studies demonstrated the structural interaction between ß-subunits of Na+ (Nav1.5) and K+ (Kv4.3) channels. Here, we identified the dipeptidyl peptidase-like protein-10 (DPP10), which is known to modulate Kv4.3-current kinetics, as a new regulator of Nav1.5 channels. METHODS: We assessed DPP10 expression in the healthy and diseased human heart and we studied the functional effects of DPP10 on the Na+ current in isolated rat cardiomyocytes expressing DPP10 after adenoviral gene-transfer (DPP10ad). RESULTS: DPP10 mRNA and proteins were detected in human ventricle, with higher levels in patients with heart failure. In rat cardiomyocytes, DPP10ad significantly reduced upstroke velocity of action potentials indicating reduction in Na+-current density. DPP10 significantly shifted the voltage-dependent Na+ channel activation and inactivation curve to more positive potentials, resulting in greater availability of Na+ channels for activation, along with increasing window Na+ current. In addition, time-to-peak Na+ current was reduced, whereas time course of recovery from inactivation was significantly accelerated by DPP10ad. DPP10 co-immunoprecipitated with Nav1.5 channels in human ventricles, confirming their physical interaction. CONCLUSION: We provide first evidence that DPP10 interacts with Nav1.5 channels, linking Na+- and K+-channel complexes in the heart. Our data suggest that increased ventricular DPP10 expression in heart failure might promote arrhythmias by decreasing peak Na+ current, while increasing window Na+ current and channel re-openings due to accelerated recovery from inactivation.

Manipulation of dipeptidylpeptidase 10 in mouse and human in vivo and in vitro models indicates a protective role in asthma.

We previously identified dipeptidylpeptidase 10 (DPP10) on chromosome 2 as a human asthma susceptibility gene, through positional cloning. Initial association results were confirmed in many subsequent association studies but the functional role of DPP10 in asthma remains unclear. Using the MRC Harwell N-ethyl-N-nitrosourea (ENU) DNA archive, we identified a point mutation in Dpp10 that caused an amino acid change from valine to aspartic acid in the ß-propeller region of the protein. Mice carrying this point mutation were recovered and a congenic line was established (Dpp10145D ). Macroscopic examination and lung histology revealed no significant differences between wild-type and Dpp10145D/145D mice. However, after house dust mite (HDM) treatment, Dpp10 mutant mice showed significantly increased airway resistance in response to 100 mg/ml methacholine. Total serum IgE levels and bronchoalveolar lavage (BAL) eosinophil counts were significantly higher in homozygotes than in control mice after HDM treatment. DPP10 protein is present in airway epithelial cells and altered expression is observed in both tissue from asthmatic patients and in mice following HDM challenge. Moreover, knockdown of DPP10 in human airway epithelial cells results in altered cytokine responses. These results show that a Dpp10 point mutation leads to increased airway responsiveness following allergen challenge and provide biological evidence to support previous findings from human genetic studies. This article has an associated First Person interview with the first author of the paper.

Prenatal Alcohol Exposure Is Associated With Adverse Cognitive Effects and Distinct Whole-Genome DNA Methylation Patterns in Primary School Children.

Prenatal alcohol exposure (PAE) is known to elicit a broad range of systemic effects, including neurophysiological alterations that result in adverse behavioral and cognitive outcomes. However, molecular pathways underlying these long-term intrauterine effects remain to be investigated. Here, we tested a hypothesis that PAE may lead to epigenetic alterations to the DNA resulting in attentional and cognitive alterations of the children. We report the results of the study that included 156 primary school children of the Franconian Cognition and Emotion Studies (FRANCES) cohort which were tested for an objective marker of PAE, ethyl glucuronide (EtG) in meconium at birth. Thirty-two newborns were found to be exposed to alcohol with EtG values above 30 ng/g (EtG+). Previously we described PAE being associated with lower IQ and smaller amplitude of the event-related potential component P3 in go trials (Go-P3), which indicates a reduced capacity of attentional resources. Whole-genome methylation analysis of the buccal cell DNA revealed 193 differentially methylated genes in children with positive meconium EtG, that were clustered into groups involved in epigenetic modifications, neurodegeneration, neurodevelopment, axon guidance and neuronal excitability. Furthermore, we detected mediation effects of the methylation changes in DPP10 and SLC16A9 genes on the EtG related cognitive and attention-related deficits. Our results suggest that system-wide epigenetic changes are involved in long-term effects of PAE. In particular, we show an epigenetic mediation of PAE effects on cognition and attention-related processes.

Use of clinical chromosomal microarray in Chinese patients with autism spectrum disorder-implications of a copy number variation involving DPP10.

BACKGROUND: Array comparative genomic hybridization (aCGH) is recommended as a first-tier genetic test for children with autism spectrum disorder (ASD). However, interpretation of results can often be challenging partly due to the fact that copy number variants (CNVs) in non-European ASD patients are not well studied. To address this literature gap, we report the CNV findings in a cohort of Chinese children with ASD. METHODS: DNA samples were obtained from 258 Chinese ASD patients recruited from a child assessment center between January 2011 and August 2014. aCGH was performed using NimbleGen-CGX-135k or Agilent-CGX 60k oligonucleotide array. Results were classified based on existing guidelines and literature. RESULTS: Ten pathogenic CNVs and one likely pathogenic CNV were found in nine patients, with an overall diagnostic yield of 3.5%. A 138 kb duplication involving 3' exons of DPP10 (arr[GRCh37] 2q14.1(116534689_116672358)x3), reported to be associated with ASD, was identified in one patient (0.39%). The same CNV was reported as variant of uncertain significance (VUS) in DECIPHER database. Multiple individuals of typical development carrying a similar duplication were identified among our ancestry-matched control with a frequency of 6/653 (0.92%) as well as from literature and genomic databases. CONCLUSIONS: The DPP10 duplication is likely a benign CNV polymorphism enriched in Southern Chinese with a population frequency of ~1%. This highlights the importance of using ancestry-matched controls in interpretation of aCGH findings.

Coexpression of auxiliary subunits KChIP and DPPL in potassium channel Kv4-positive nociceptors and pain-modulating spinal interneurons.

Subthreshold A-type K(+) currents (ISA s) have been recorded from the somata of nociceptors and spinal lamina II excitatory interneurons, which sense and modulate pain, respectively. Kv4 channels are responsible for the somatodendritic ISA s. Accumulative evidence suggests that neuronal Kv4 channels are ternary complexes including pore-forming Kv4 subunits and two types of auxiliary subunits: K(+) channel-interacting proteins (KChIPs) and dipeptidyl peptidase-like proteins (DPPLs). Previous reports have shown Kv4.3 in a subset of nonpeptidergic nociceptors and Kv4.2/Kv4.3 in certain spinal lamina II excitatory interneurons. However, whether and which KChIP and DPPL are coexpressed with Kv4 in these ISA -expressing pain-related neurons is unknown. In this study we mapped the protein distribution of KChIP1, KChIP2, KChIP3, DPP6, and DPP10 in adult rat dorsal root ganglion (DRG) and spinal cord by immunohistochemistry. In the DRG, we found colocalization of KChIP1, KChIP2, and DPP10 in the somatic surface and cytoplasm of Kv4.3(+) nociceptors. KChIP3 appears in most Aß and Aδ sensory neurons as well as a small population of peptidergic nociceptors, whereas DPP6 is absent in sensory neurons. In the spinal cord, KChIP1 is coexpressed with Kv4.3 in the cell bodies of a subset of lamina II excitatory interneurons, while KChIP1, KChIP2, and DPP6 are colocalized with Kv4.2 and Kv4.3 in their dendrites. Within the dorsal horn, besides KChIP3 in the inner lamina II and lamina III, we detected DPP10 in most projection neurons, which transmit pain signal to brain. The results suggest the existence of Kv4/KChIP/DPPL ternary complexes in ISA -expressing nociceptors and pain-modulating spinal interneurons.

Identification of potential novel interaction partners of the sodium-activated potassium channels Slick and Slack in mouse brain.

The sodium-activated potassium channels Slick (Slo2.1, KCNT2) and Slack (Slo2.2, KCNT1) are paralogous channels of the Slo family of high-conductance potassium channels. Slick and Slack channels are widely distributed in the mammalian CNS and they play a role in slow afterhyperpolarization, generation of depolarizing afterpotentials and in setting and stabilizing the resting potential. In the present study we used a combined approach of (co)-immunoprecipitation studies, Western blot analysis, double immunofluorescence and mass spectrometric sequencing in order to investigate protein-protein interactions of the Slick and Slack channels. The data strongly suggest that Slick and Slack channels co-assemble into identical cellular complexes. Double immunofluorescence experiments revealed that Slick and Slack channels co-localize in distinct mouse brain regions. Moreover, we identified the small cytoplasmic protein beta-synuclein and the transmembrane protein 263 (TMEM 263) as novel interaction partners of both, native Slick and Slack channels. In addition, the inactive dipeptidyl-peptidase (DPP 10) and the synapse associated protein 102 (SAP 102) were identified as constituents of the native Slick and Slack channel complexes in the mouse brain. This study presents new insights into protein-protein interactions of native Slick and Slack channels in the mouse brain.

Forecasting of Molecular Sponge Mechanism Mediated by LOC389023 in Patients with Intractable Temporal Lobe Epilepsy / 中山大学学报(医学科学版)

[Objective]To forecast the sponge mechanism mediated by LOC389023 in patients with intractable temporal lobe epilepsy(TLE),through investigating the expression of microRNA interacted with dipeptidyl peptidase 10(DPP10)and LOC389023.[Methods]The expression of DPP10 and Kv4.3 were detected in 15 temporal neocortex from patients with brain trauma (control group)and in 26 temporal neocortex from patients with intractable TLE(epilepsy group)by western blot(WB)and immunohisto?chemical(IHC)staining. The location of DPP10 and voltage dependent potassium channel 4.3(Kv4.3)was detected by immunofluo?rescent(IF)staining. The interaction between DPP10 and Kv4.3 was testified by co-immunoprecipitation(Co-IP). The expression of microRNA obtained by softwares(miRanda,Pita,TargetScan and miRDB)was detected by qPCR.[Results]IHC and WB showed an increased expression of DPP10(P0.05). But decreased expression of LOC389023 and miR-140-5p and increased expression of miR-25-3p and miR-367-3p were found in epilepsygroup compared to control group (P < 0.05).[Conclusion]miR-25-3p and miR-367-3p may be regulated by LOC389023 through the sponge mechanism followed by altered expression of DPP10 in intractable temporal lobe epilepsy.