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PubMed2004

Transcription profiling of gene expression in drug discovery and development: the NCI experience.

Transcript profiling, using microarray or other analogous technologies, to query on a large-scale the expression of genes in tumours or their derivative cell lines has numerous potential uses in oncology drug discovery and development. Characterisation of genes expressed in tumours may allow tumours to be separated into subsets defining subtypes that have a distinctive pathway utilisation. The molecular entities comprising the pathways which distinguish one disease subset from another then become potential candidate drug targets. Alternatively, gene expression patterns may be correlated with the degree of antiproliferative effect of candidate drug leads. This can reveal aspects of the drug's action that could serve to provide a further basis for benchmarking the generation of analogues or provide important information about pathways potentially modulated by the drug in achieving cytotoxicity. New information is emerging that the expression of drug transport-related molecules is a major variable that can be usefully explored using gene expression data, and the features promoting successful drug handling by the tumour cell may be an additional variable which can be illuminated by gene expression studies.

Antineoplastic Agents↗

PubMed2025

Heme oxygenase 1 (HO-1) is a drug target for reversing cisplatin resistance in non-small cell lung cancer.

INTRODUCTION: Platinum-based drugs, the most widely used chemotherapeutic drugs in clinical oncology, have long faced the problem of drug resistance, which is urgently in need of resolution. Identifying biomarkers of drug resistance may help reduce platinum resistance and improve therapeutic efficacy. OBJECTIVES: This study aims to identify potential biomarkers associated with the development of cisplatin resistance in non-small cell lung cancer (NSCLC) and explore mechanisms to overcome chemoresistance. METHODS: NSCLC cisplatin resistance cell lines were constructed, and transcriptome sequencing was performed. Results were validated using Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. Molecular docking, proteomics sequencing, and in vitro and in vivo experiments were conducted to evaluate the role of Heme Oxygenase 1 (HO-1) in cisplatin resistance. RESULTS: NSCLC cisplatin resistance cell lines, GEO and TCGA data identified HMOX1, downstream of Nrf2, as a key drug resistance gene induced by cisplatin. Activation of the Nrf2/HO-1 pathway was found to induce ferroptosis resistance, a critical mechanism of cisplatin resistance. Candidate compounds SB 202190 and Nordihydroguaiaretic acid (NDGA) effectively reactivated ferroptosis by inhibiting HO-1, thereby increasing cisplatin sensitivity. CONCLUSION: The Nrf2/HO-1 pathway is a significant contributor to cisplatin resistance in NSCLC. Targeting HO-1 with SB 202190 and NDGA presents a promising strategy to overcome resistance and improve chemotherapy outcomes.

Cisplatin↗

PubMed2026

Matrine Alleviates Sepsis-Induced Acute Lung Injury by Reinforcing NQO1/SLC7A11/GPX4-Associated Anti-Ferroptotic Defenses and Attenuating NF-κB-Driven Inflammation.

BACKGROUND: Sepsis triggers dysregulated systemic inflammation and multiple-organ dysfunction, with the lungs being particularly susceptible to injury. Sepsis-induced acute respiratory distress syndrome (ARDS) is mainly driven by TLR4/NF-κB-mediated hyperinflammation and alveolar macrophage activation. Matrine, a bioactive alkaloid derived from Sophora flavescens, has been reported to modulate redox homeostasis and ferroptosis-associated lipid peroxidation. However, the target-specific mechanisms underlying its effects on ferroptosis and inflammatory signaling in sepsis-induced acute lung injury (SALI) remain incompletely understood. PURPOSE: This study aimed to evaluate the therapeutic effects of matrine in a cecal ligation and puncture (CLP)-induced SALI model and to determine whether its protective effects involve reinforcement of NQO1/SLC7A11/GPX4-associated anti-ferroptotic defenses and suppression of NF-κB-driven inflammation. METHODS: We analyzed the single-cell RNA-sequencing (scRNA-seq) dataset GSE273924 to characterize CD45-enriched pulmonary immune-cell subsets in sham mice and mice with intratracheal Escherichia coli-induced pneumonia. Network pharmacology and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed to predict Kushen (KS)-related targets and pathways associated with SALI. Differential expression analysis and weighted gene co-expression network analysis (WGCNA) of GSE245013 were used to identify candidate targets. Matrine-NQO1 binding and intracellular target engagement were evaluated using molecular docking, molecular dynamics simulations, surface plasmon resonance (SPR), and the cellular thermal shift assay (CETSA). The therapeutic effects of matrine were assessed in mice with CLP-induced SALI and in lipopolysaccharide (LPS)-stimulated MH-S cells. Lung histopathology, inflammatory cytokine production, target protein expression, ferroptosis-associated indicators, and NF-κB activation were evaluated using molecular, biochemical, and histological assays. The functional contribution of NQO1 was further examined using the NQO1 inhibitor ES936. RESULTS: scRNA-seq analysis of GSE273924 revealed substantial remodeling of the CD45-enriched pulmonary immune-cell landscape in mice with intratracheal E. coli-induced pneumonia, including macrophage transcriptional programs associated with ferroptosis and inflammatory signaling. Integrated network pharmacology and bioinformatics analyses prioritized NQO1 as a candidate target of matrine and identified NF-κB signaling as a potentially relevant pathway. Molecular docking, molecular dynamics simulations, SPR, and CETSA supported matrine-NQO1 binding and intracellular target engagement. Functionally, matrine improved survival, attenuated lung injury, reinforced NQO1/SLC7A11/GPX4-associated anti-ferroptotic defenses, and suppressed NF-κB activation in CLP mice. Similar protective effects were observed in LPS-stimulated MH-S cells. ES936 partially attenuated the matrine-mediated improvements in cell viability, redox homeostasis, ferroptosis-associated indicators, and NF-κB p65 phosphorylation, supporting a functional contribution of NQO1 to the protective effects of matrine. CONCLUSION: Matrine alleviates SALI by reinforcing NQO1/SLC7A11/GPX4-associated anti-ferroptotic defenses and attenuating NF-κB-driven inflammation.

Animals↗

PubMed2001

[Molecular principles of induction and progression of arthrosis].

From a morphological point of view, osteoarthritis is characterized by continuous loss of the cartilage matrix, an increased density of the subchondral bone, and partial involvement of the synovial compartment. Research activities are focussing on gene expression and gene regulation in normal and osteoarthritic cartilage to develop prognostic markers and new therapeutic strategies. In general, chondrocytes from normal adult articular cartilage show low metabolic activity. However in osteoarthritis, activation and differentiation of chondrocytes occur. Activation involves anabolic pathways such as an enhanced expression of type II collagen as well as catabolic patterns such as the increased expression of matrix metalloproteinases. These metabolic pathways are unbalanced, leading to insufficient cartilage architecture, unable to meet the requirements for mechanical stability and load compensation. In osteoarthritis, chondrocyte differentiation is characterized by the expression of type X collagen. Further differentiation stages have been observed as shown for the expression of osteocalcin, osteopontin, or alkaline phosphatase in articular cartilage. This altered expression pattern of chondrocytes is likely to influence the biochemical and biomechanical properties of the cartilage matrix. In conclusion, new analytic and comparative methods to analyze gene and protein expression offer powerful tools to elucidate candidate genes in osteoarthritis. Detailed information on the regulatory pathways will be the basis for modulation of chondrocyte behavior and, therefore, may lead to new therapeutic approaches in the treatment of osteoarthritis.

Alkaline Phosphatase↗

PubMed2003

Genome-wide analysis of the L-methionine biosynthetic pathway in Corynebacterium glutamicum by targeted gene deletion and homologous complementation.

The genome sequence of Corynebacterium glutamicum, a gram-positive soil bacterium widely used as an amino acid producer, was analyzed by a similarity-based approach to elucidate the pathway for the biosynthesis of L-methionine. The functions of candidate ORFs were derived by gene deletion and, if necessary, by homologous complementation of suitable mutants. Of nine candidate ORFs (four of which were known previously), seven ORFs (cg0754 (metX), cg0755 (metY), cg1290 (metE), cg1702 (metH), cg2383 (metF), cg2536 (aecD), and cg2687 (metB)) were demonstrated to be part of the pathway while two others (cg0961 and cg3086) could be excluded. C. glutamicum synthesizes methionine in three, respectively four steps, starting from homoserine. C. glutamicum possesses two genes with similarity to homoserine acetyltransferases but only MetX can act as such while Cg0961 catalyzes a different, unknown reaction. For the incorporation of the sulfur moiety, the known functions of MetY and MetB could be confirmed and AecD was proven to be the only functional cystathionine beta-lyase in C. glutamicum, while Cg3086 can act neither as cystathionine gamma-synthase nor as cystathionine beta-lyase. Finally, MetE and MetH, which catalyze the conversion of L-homocysteine to L-methionine, could be newly identified, together with MetF which provides the necessary N(5)-methyltetrahydrofolate.

Amino Acid Sequence↗

PubMed2004

Pharmacogenetics of antidepressants and antipsychotics: the contribution of allelic variations to the phenotype of drug response.

Genetic factors contribute to the phenotype of drug response. We systematically analyzed all available pharmacogenetic data from Medline databases (1970-2003) on the impact that genetic polymorphisms have on positive and adverse reactions to antidepressants and antipsychotics. Additionally, dose adjustments that would compensate for genetically caused differences in blood concentrations were calculated. To study pharmacokinetic effects, data for 36 antidepressants were screened. We found that for 20 of those, data on polymorphic CYP2D6 or CYP2C19 were found and that in 14 drugs such genetic variation would require at least doubling of the dose in extensive metabolizers in comparison to poor metabolizers. Data for 38 antipsychotics were examined: for 13 of those CYP2D6 and CYP2C19 genotype was of relevance. To study the effects of genetic variability on pharmacodynamic pathways, we reviewed 80 clinical studies on polymorphisms in candidate genes, but those did not for the most part reveal significant associations between neurotransmitter receptor and transporter genotypes and therapy response or adverse drug reactions. In addition associations found in one study could not be replicated in other studies. For this reason, it is not yet possible to translate pharmacogenetic parameters fully into therapeutic recommendations. At present, antidepressant and antipsychotic drug responses can best be explained as the combinatorial outcome of complex systems that interact at multiple levels. In spite of these limitations, combinations of polymorphisms in pharmacokinetic and pharmacodynamic pathways of relevance might contribute to identify genotypes associated with best and worst responders and they may also identify susceptibility to adverse drug reactions.

Alleles↗

PubMed2004

Are the extracellular [correction of extracelluar] pathways a conduit for the delivery of therapeutics to the brain?

Most drugs with central nervous system (CNS) activity enter the brain either by diffusing across the membranes which comprise the blood-brain barrier (BBB) or by being transported by carrier systems across those membranes. Substances which cannot cross the BBB by one of these mechanisms, like serum albumin, are virtually excluded from the CNS. However, this exclusion is not absolute. Cerebrospinal fluid (CSF) levels of albumin, for example, are about 0.5% those of serum levels. Albumin enters the CNS through a variety of pathways collectively termed the extracellular pathways. Any circulating substance can, in theory, use these pathways to enter the CNS. But, traditional drug development has ignored this pathway. To approach even the CSF/serum ratio of 0.5%, a candidate therapeutic would need to meet several criterion: long half-life in blood, small volume of distribution, high potency in the CNS, and absence of brain-to-blood efflux. Two emerging therapeutics which are likely exerting their CNS effects by way of the extracellular pathways are antibodies directed against amyloid beta protein (ABP) and erythropoietin (Epo) used in the treatment of stroke. These examples suggest that the extracellular pathways are an option for the delivery of certain therapeutics to the brain.

Animals↗

PubMed2001

Dissection of defence response pathways in rice.

The cloning of major resistance genes has led to a better understanding of the molecular biology of the steps for induction of resistance, yet much remains to be discovered about the downstream genes that collectively confer resistance, i.e. the defence response (DR) genes. We are dissecting the pathways contributing to resistance in rice by identifying a collection of mutants with deletions or other structural rearrangements in DR genes. The collection of rice mutants has been screened for many characters, including increased susceptibility or resistance to Magnaporthe grisea and Xanthomonas oryzae pv. oryzae. A collection of enhanced sequence tags (ESTs) and putative DR genes has been established to facilitate detection of mutants with deletions in DR genes. Arrays of DR genes will be used to create gene expression profiles of interesting mutants. Successful application of the mutant screen will have broad utility in identifying candidate genes involved in disease response and other metabolic pathways.

Expressed Sequence Tags↗

PubMed2005

Killing time for cancer cells.

As the signalling pathways that control cellular proliferation and death are unravelled, a range of targets have emerged as candidates for molecular cancer therapy. For their survival, cancer cells depend on a few highly activated signalling pathways; inhibition of these pathways has a strong apoptotic effect and can lead to tumour regression. But drugs that exploit this weakness, such as imatinib, have not cured patients: withdrawal of the drug leads to disease recurrence, and sustained treatment leads to the emergence of drug-resistant clones. Can cancer be cured, or will it have to be controlled as a chronic disease?

Angiogenesis Inhibitors↗

PubMed2006

Characterization of cell-type specific profiles in tissues and isolated cells from squamous cell carcinomas of the lung.

Lung cancer accounts for 28% of all cancer deaths, a higher percentage than any other human cancer. Squamous Cell Carcinoma (SqCC) is the most common lung neoplasm and is a tumor that is extensively associated with tobacco use. Despite the association of many genetic alterations with lung cancer, the precise molecular mechanisms of tumorigenesis, for the most part, remain ambiguous. Although many studies of lung cancer have used global transcript profiling approaches designed to uncover genes or pathways that are important in lung tumorigenesis, no strong candidates have emerged. A lack of concurrence amongst these various studies can be attributed, in a large part, to the cellular heterogeneity within lung tissue. We have attempted to reduce this complication by designing a profiling strategy that will minimize the confounding involvement of tissue heterogeneity in gene expression of lung tumors. Specifically, we have profiled transcript expression levels in both isolated cells and tissues from SqCC and normal samples. Our strategy consists of combining and subtracting the input of these various cell types which has produced a unique transcript profile of the squamous carcinoma cell. We then analyzed the data using Pathways Assist analysis software to determine which processes may be involved in SqCC tumorigenesis. The MAP/ERK pathway involved in growth and differentiation was the pathway that was most frequently identified across all comparisons. In addition, biological interaction networks of the SqCC profile identified IL-8 as playing a potentially important role SqCC development.

Adenocarcinoma↗

PubMed1999

Leukaemia disease genes: large-scale cloning and pathway predictions.

Retroviral insertional mutagenesis in BXH2 and AKXD recombinant inbred mice induces a high incidence of myeloid or B- and T-cell leukaemia and the proviral integration sites in the leukaemias provide powerful genetic tags for disease gene identification. Some of the disease genes identified by proviral tagging are also associated with human disease, validating this approach for human disease gene identification. Although many leukaemia disease genes have been identified over the years, many more remain to be cloned. Here we describe an inverse PCR (IPCR) method for proviral tagging that makes use of automated DNA sequencing and the genetic tools provided by the Mouse Genome Project, which increases the throughput for disease gene identification. We also use this IPCR method to clone and analyse more than 400 proviral integration sites from AKXD and BXH2 leukaemias and, in the process, identify more than 90 candidate disease genes. Some of these genes function in pathways already implicated in leukaemia, whereas others are likely to define new disease pathways. Our studies underscore the power of the mouse as a tool for gene discovery and functional genomics.

Animals↗

PubMed2001

Cytochrome P450 polymorphisms as risk factors for steroid hormone-related cancers.

The development of cancers of the breast, endometrium, ovaries and possibly prostate is modulated by steroid hormones. Many steroids and environmental carcinogens are subject to cytochrome P450 (P450)-mediated metabolism that generates reactive metabolites and modulates steroid potency, thereby influencing tumor initiation and promotion respectively. These pathways, which are modulated by polymorphisms in P450 genes, are therefore likely to play an important role in the etiology of hormone-related cancers. Several groups have evaluated genotypes of xenobiotic- and steroid-metabolizing P450 enzymes as risk factors for hormone-related cancers. Polymorphisms in P450s that are specifically involved in the metabolism of steroids appear to be single risk factors. The situation is less clear for xenobiotic-metabolizing P450s. For these genes, only combined genotypes of several P450s or combined genotypes of P450s together with other enzymes have been clearly correlated with disease frequency. Success in identifying the appropriate combination of candidate genes requires a thorough knowledge of the metabolic pathways and enzyme systems that control the initial stages of carcinogenesis, as will be illustrated in this review.

Animals↗

PubMed2026

Exploring the mechanism of Acanthopanax in treating vertigo: A network pharmacology and molecular docking study.

Acanthopanax has therapeutic efficacy against vertigo; however, the underlying mechanism remains unclear. This study aimed to elucidate the mechanism by which Acanthopanax treats vertigo through integrated network pharmacology and molecular docking techniques, and retrieved all target genes of Acanthopanax for vertigo treatment from July to October 2025. Vertigo-related target genes were subsequently identified from public databases, including GeneCards and Online Mendelian Inheritance in Man. The intersection between Acanthopanax-derived targets and vertigo-related targets was analyzed to identify candidate target genes. Using the STRING platform, we constructed protein-protein interaction networks for the identified candidate targets and mined the core functional modules within these networks. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed on candidate targets via the clusterProfiler package. A carp bile poisoning-liver injury target-pathway network was constructed via Cytoscape 3.8.2 software, network topology analysis was conducted, and the core components and targets were screened. The results found that A total of 295 candidate targets for the treatment of vertigo caused by Eleutherococcus senticosus were identified. Pathway enrichment analysis revealed that Eleutherococcus senticosus treatment for vertigo may be closely associated with pathways related to IL-17, TNF, phosphoinositide 3-kinase (PI3K)-Akt, p53, HIF-1, and Forkhead box O signaling. The core targets for the treatment of A. senticosus vertigo include TP53, AKT1, STAT3, TNF, and JUN. Network pharmacology and molecular docking studies suggest that A. senticosus may treat vertigo by regulating targets such as JUN, TNF, AKT1, STAT3, and STAT3 through pathways such as the IL-17, TNF, phosphoinositide 3-kinase-Akt, p53, HIF-1, and Forkhead box O signaling pathways. These mechanisms warrant further investigation in future o and in vitro studies.

Molecular Docking Simulation↗

PubMed1999

A Drosophila TNF-receptor-associated factor (TRAF) binds the ste20 kinase Misshapen and activates Jun kinase.

Two families of protein kinases that are closely related to Ste20 in their kinase domain have been identified - the p21-activated protein kinase (Pak) and SPS1 families [1-3]. In contrast to Pak family members, SPS1 family members do not bind and are not activated by GTP-bound p21Rac and Cdc42. We recently placed a member of the SPS1 family, called Misshapen (Msn), genetically upstream of the c-Jun amino-terminal (JNK) mitogen-activated protein (MAP) kinase module in Drosophila [4]. The failure to activate JNK in Drosophila leads to embryonic lethality due to the failure of these embryos to stimulate dorsal closure [5-8]. Msn probably functions as a MAP kinase kinase kinase kinase in Drosophila, activating the JNK pathway via an, as yet, undefined MAP kinase kinase kinase. We have identified a Drosophila TNF-receptor-associated factor, DTRAF1, by screening for Msn-interacting proteins using the yeast two-hybrid system. In contrast to the mammalian TRAFs that have been shown to activate JNK, DTRAF1 lacks an amino-terminal 'Ring-finger' domain, and overexpression of a truncated DTRAF1, consisting of only its TRAF domain, activates JNK. We also identified another DTRAF, DTRAF2, that contains an amino-terminal Ring-finger domain. Msn specifically binds the TRAF domain of DTRAF1 but not that of DTRAF2. In Drosophila, DTRAF1 is thus a good candidate for an upstream molecule that regulates the JNK pathway by interacting with, and activating, Msn. Consistent with this idea, expression of a dominant-negative Msn mutant protein blocks the activation of JNK by DTRAF1. Furthermore, coexpression of Msn with DTRAF1 leads to the synergistic activation of JNK. We have extended some of these observations to the mammalian homolog of Msn, Nck-interacting kinase (NIK), suggesting that TRAFs also play a critical role in regulating Ste20 kinases in mammals.

Amino Acid Sequence↗

PubMed2005

Salivary glands as a potential gene transfer target for gene therapeutics of some monogenetic endocrine disorders.

Salivary glands (SGs) exhibit several important features which are also common to endocrine glands: self-containment due to a surrounding capsule, highly efficient protein production and the ability to secrete proteins into the bloodstream. We have hypothesized that SGs are potentially useful as gene transfer targets for the correction of inherited monogenetic endocrine disorders. In the present communication, we extend our studies and attempt to test our hypothesis by comparing the efficacy of two commonly used viral vectors and the resulting serum and salivary distribution of transgene encoded hormones. A low dose (5 x10(9) particles) of either an adenoviral serotype 5 (Ad5) vector encoding the human erythropoietin (hEPO) cDNA or an adeno-associated virus sero-type 2 (AAV2) vector encoding either the hEPO or human growth hormone (hGH) cDNA was administered to individual submandibular SGs of Balb/c mice. Serum and salivary hEPO and hGH levels were determined at defined time points. Two additional recombinant viruses encoding enhanced green fluorescence protein (GFP) were also used (AdGFP and AAVGFP) in order to perform immunohistochemical analyses of transgenic protein localization in SG sections post-administration. AAV2 vectors led to stable gene transfer unlike the results with the Ad5 vectors. Indeed, in one mouse we observed hEPO production for a period of two years after administration of AAVhEPO to SGs. hEPO, which is a constitutive pathway secretory protein, was readily secreted into the bloodstream from the SGs, yielding therapeutically adequate serum levels. Conversely, hGH, a regulated secretory pathway protein, was preferentially secreted into saliva. SGs may be an attractive candidate target tissue for gene therapeutics of some monogenetic endocrine deficiency disorders. At present, AAV2 vectors seem particularly useful for such applications, and transgenes encoding constitutive secretory pathway hormones are more suitable for this application with SGs than those encoding regulated secretory pathway hormones.

Adenoviridae↗

PubMed2004

Polymorphisms in the prostaglandin E2 receptor subtype 2 gene confer susceptibility to aspirin-intolerant asthma: a candidate gene approach.

Aspirin-intolerant asthma (AIA) is a subtype of bronchial asthma characterized by development of bronchoconstriction evoked by non-steroidal anti-inflammatory drugs (NSAIDs). NSAIDs inhibit the cyclooxygenase pathway, leading to enhancement of the lipoxygenase pathway. We evaluated allelic association of 370 single nucleotide polymorphisms (SNPs) of 63 candidate genes, mostly from the arachidonic acid metabolic cascade, with AIA. After two rounds of screening with 198 AIA patients, multiple SNPs in the prostaglandin E(2) receptor subtype 2 (EP2) gene were associated with AIA (P<0.05). Among the 77 SNPs identified in the EP2 gene, we selected 17 SNPs on the basis of linkage disequilibrium and allelic frequencies (minor allele frequency >0.1) for further association study. SNPs in the promoter region of the EP2 gene, uS5, uS5b, and uS7, were significantly associated with AIA (permutation P=0.039-0.001). Analysis of haplotypes constructed according to the LD pattern showed a significant association with AIA (permutation P=0.001). The most significantly associated SNP, uS5, located in the regulatory region of the EP2 gene, was in a STATs-binding consensus sequence [AIA 31.1% versus control 22.1% (permutation P=0.0016) or versus aspirin-tolerant asthma 22.2% (permutation P=0.0017)]. Although STAT1 binding was not observed in gel mobility shift assay with HeLa nuclear extract, an unidentified protein was specifically bound to the allelic sequence. In in vitro reporter assay in HCT116 cells, the site containing the uS5 allele showed reduced transcription activity. Taken together, these results suggest that uS5 allele serves as a target of a transcription repressor protein. A functional SNP of the EP2 gene associated with risk of AIA should decrease the transcription level, resulting in reduction of the PGE(2) braking mechanism of inflammation and involvement in the molecular mechanism underlying AIA.

Aspirin↗

PubMed2006

Association of DSC1, a gene modulated by adrenergic stimulation, with Alzheimer's disease.

Alzheimer's disease (AD) is a complex multifactorial disorder involving a number of genetic and environmental factors, with severe head injury consistently reported as a major non-genetic risk factor. The adrenergic activation that occurs during major trauma increases cAMP levels, therefore the cAMP signaling pathway might be involved in AD pathogenesis. Time course of candidate gene expression following adrenergic stimulation with isoproterenol was assayed in neuroblastoma cells by quantitative reverse transcription (RT)-PCR. Then, genetic association studies of polymorphisms in several of these candidate genes were performed. Association studies in two independent case-control samples showed a polymorphism in DSC1, encoding desmocollin 1--a member of the desmosomal cadherins--which modulated AD susceptibility in a gender-specific manner. These results are in accordance with the potential involvement of the adrenergic signaling pathway in AD pathogenesis.

Adrenergic beta-Agonists↗

PubMed2004

Morphologic characterization of rat taste receptor cells that express components of the phospholipase C signaling pathway.

Rat taste buds contain three morphologically distinct cell types that are candidates for taste transduction. The physiologic roles of these cells are, however, not clear. Inositol 1,4,5-triphosphate (IP(3)) has been implicated as an important second messenger in bitter, sweet, and umami taste transductions. Previously, we identified the type III IP(3) receptor (IP(3)R3) as the dominant isoform in taste receptor cells. In addition, a recent study showed that phospholipase Cbeta(2) (PLCbeta(2)) is essential for the transduction of bitter, sweet, and umami stimuli. IP(3)R3 and PLCbeta(2) are expressed in the same subset of cells. To identify the taste cell types that express proteins involved in PLC signal transduction, we used 3,3'diaminobenzidine tetrahydrochloride immunoelectron microscopy and fluorescence microscopy to identify cells with IP(3)R3. Confocal microscopy was used to compare IP(3)R3 or PLCbeta(2) immunoreactivity with that of some known cell type markers such as serotonin, protein gene-regulated product 9.5, and neural cell adhesion molecule. Here we show that a large subset of type II cells and a small subset of type III cells display IP(3)R3 immunoreactivity within their cytoplasm. These data suggest that type II cells are the principal transducers of bitter, sweet, and umami taste transduction. However, we did not observe synapses between type II taste cells and nerve fibers. Interestingly, we observed subsurface cisternae of smooth endoplasmic reticulum at the close appositions between the plasma membrane of type II taste cells and nerve processes. We speculate that some type II cells may communicate to the nervous system via subsurface cisternae of smooth endoplasmic reticulum in lieu of conventional synapses.

Animals↗