Characterization of age-associated gene expression changes in mouse sweat glands.

Evaporation of sweat on the skin surface is the major mechanism for dissipating heat in humans. The secretory capacity of sweat glands (SWGs) declines during aging, leading to heat intolerance in the elderly, but the mechanisms responsible for this decline are poorly understood. We investigated the molecular changes accompanying SWG aging in mice, where sweat tests confirmed a significant reduction of active SWGs in old mice relative to young mice.

Contribution of ADAMTS13-independent VWF regulation in sickle cell disease.

Background: Von Willebrand factor (VWF) is elevated in sickle cell disease (SCD) and contributes to vaso-occlusion through its thrombogenic properties. VWF is regulated by ADAMTS13, a plasma protease that cleaves VWF into less bioactive multimers. Independent investigations have shown VWF to be elevated in SCD, whereas measurements of ADAMTS13 have been variable.

Convergence of SIRT1 and ATR signaling to modulate replication origin dormancy.

During routine genome duplication, many potential replication origins remain inactive or 'dormant'. Such origin dormancy is achieved, in part, by an interaction with the metabolic sensor SIRT1 deacetylase. We report here that dormant origins are a group of consistent, pre-determined genomic sequences that are distinguished from baseline (i.

Lipid Peroxidation Induced ApoE Receptor-Ligand Disruption as a Unifying Hypothesis Underlying Sporadic Alzheimer's Disease in Humans.

Background: Sporadic Alzheimer's disease (sAD) lacks a unifying hypothesis that can account for the lipid peroxidation observed early in the disease, enrichment of ApoE in the core of neuritic plaques, hallmark plaques and tangles, and selective vulnerability of entorhinal-hippocampal structures.

Objective: We hypothesized that 1) high expression of ApoER2 (receptor for ApoE and Reelin) helps explain this anatomical vulnerability; 2) lipid peroxidation of ApoE and ApoER2 contributes to sAD pathogenesis, by disrupting neuronal ApoE delivery and Reelin-ApoER2-Dab1 signaling cascades.

Methods: In vitro biochemical experiments; Single-marker and multiplex fluorescence-immunohistochemistry (IHC) in postmortem specimens from 26 individuals who died cognitively normal, with mild cognitive impairment or with sAD.

Targeting selenoprotein H in the nucleolus suppresses tumors and metastases by Isovalerylspiramycin I.

Background: Compared to normal cells, cancer cells exhibit a higher level of oxidative stress, which primes key cellular and metabolic pathways and thereby increases their resilience under oxidative stress. This higher level of oxidative stress also can be exploited to kill tumor cells while leaving normal cells intact. In this study we have found that isovalerylspiramycin I (ISP I), a novel macrolide antibiotic, suppresses cancer cell growth and tumor metastases by targeting the nucleolar protein selenoprotein H (SELH), which plays critical roles in keeping redox homeostasis and genome stability in cancer cells.

Intracellular RNA-tracking methods.

RNA tracking allows researchers to visualize RNA molecules in cells and tissues, providing important spatio-temporal information regarding RNA dynamics and function. Methods such as fluorescent hybridization (FISH) and molecular beacons rely on complementary oligonucleotides to label and view endogenous transcripts. Other methods create artificial chimeric transcripts coupled with bacteriophage-derived coat proteins (e.

Insulin Is Transcribed and Translated in Mammalian Taste Bud Cells.

We and others have reported that taste cells in taste buds express many peptides in common with cells in the gut and islets of Langerhans in the pancreas. Islets and taste bud cells express the hormones glucagon and ghrelin, the same ATP-sensitive potassium channel responsible for depolarizing the insulin-secreting β cell during glucose-induced insulin secretion, as well as the propeptide-processing enzymes PC1/3 and PC2. Given the common expression of functionally specific proteins in taste buds and islets, it is surprising that no one has investigated whether insulin is synthesized in taste bud cells.

Identification of senescent cell surface targetable protein DPP4.

Senescent cell accumulation in aging tissues is linked to age-associated diseases and declining function, prompting efforts to eliminate them. Mass spectrometry analysis revealed that DPP4 (dipeptidyl peptidase 4) was selectively expressed on the surface of senescent, but not proliferating, human diploid fibroblasts. Importantly, the differential presence of DPP4 allowed flow cytometry-mediated isolation of senescent cells using anti-DPP4 antibodies.

Concurrent activation of β-adrenergic receptor and blockage of GPR55 disrupts pro-oncogenic signaling in glioma cells.

Activation of β-adrenergic receptor (βAR) and deorphanized GPR55 has been shown to modulate cancer growth in diverse tumor types in vitro and in xenograft models in vivo. (R,R')-4'-methoxy-1-naphthylfenoterol [(R,R')-MNF] is a bivalent compound that agonizes βAR but inhibits GPR55-mediated pro-oncogenic responses. Here, we investigated the molecular mechanisms underlying the anti-tumorigenic effects of concurrent βAR activation and GPR55 blockade in C6 glioma cells using (R,R')-MNF as a marker ligand.

Probing extracellular Sonic hedgehog in neurons.

The bioactivity of Sonic hedgehog (Shh) depends on specific lipid modifications; a palmitate at its N-terminus and a cholesterol at its C-terminus. This dual-lipid modification makes Shh molecules lipophilic, which prevents them from diffusing freely in extracellular space. Multiple lines of evidence indicate that Shh proteins are carried by various forms of extracellular vesicles (EVs).

HuR and GRSF1 modulate the nuclear export and mitochondrial localization of the lncRNA RMRP.

Some mitochondrial long noncoding RNAs (lncRNAs) are encoded by nuclear DNA, but the mechanisms that mediate their transport to mitochondria are poorly characterized. Using affinity RNA pull-down followed by mass spectrometry analysis, we found two RNA-binding proteins (RBPs), HuR (human antigen R) and GRSF1 (G-rich RNA sequence-binding factor 1), that associated with the nuclear DNA-encoded lncRNA RMRP and mobilized it to mitochondria. In cultured human cells, HuR bound RMRP in the nucleus and mediated its CRM1 (chromosome region maintenance 1)-dependent export to the cytosol.

Induction of VEGFA mRNA translation by CoCl2 mediated by HuR.

Vascular endothelial growth factor (VEGF) A is a master regulator of neovascularization and angiogenesis. VEGFA is potently induced by hypoxia and by pathological conditions including diabetic retinopathy and tumorigenesis. Fine-tuning of VEGFA expression by different stimuli is important for maintaining tissue vascularization and organ homeostasis.

Hypoxia induces phenotypic plasticity and therapy resistance in melanoma via the tyrosine kinase receptors ROR1 and ROR2.

Unlabelled: An emerging concept in melanoma biology is that of dynamic, adaptive phenotype switching, where cells switch from a highly proliferative, poorly invasive phenotype to a highly invasive, less proliferative one. This switch may hold significant implications not just for metastasis, but also for therapy resistance. We demonstrate that phenotype switching and subsequent resistance can be guided by changes in expression of receptors involved in the noncanonical Wnt5A signaling pathway, ROR1 and ROR2.

The biarylpyrazole compound AM251 alters mitochondrial physiology via proteolytic degradation of ERRα.

The orphan nuclear receptor estrogen-related receptor alpha (ERRα) directs the transcription of nuclear genes involved in energy homeostasis control and the regulation of mitochondrial mass and function. A crucial role for controlling ERRα-mediated target gene expression has been ascribed to the biarylpyrazole compound 1-(2,4-dichlorophenyl)-5-(4-iodophenyl)-4-methyl-N-1-piperidinyl-1H-pyrazole-3-carboxamide (AM251) through direct binding to and destabilization of ERRα protein. Here, we provide evidence that structurally related AM251 analogs also have negative impacts on ERRα protein levels in a cell-type-dependent manner while having no deleterious actions on ERRγ.

Reduction of AP180 and CALM produces defects in synaptic vesicle size and density.

Clathrin assembly proteins AP180 and CALM regulate the assembly of clathrin-coated vesicles (CCVs), which mediate diverse intracellular trafficking processes, including synaptic vesicle (SV) recycling at the synapse. Although studies using several invertebrate model systems have indicated a role for AP180 in SV recycling, less is known about AP180's or CALM's function in the synapse of mammalian neurons. In this study, we examined synapses of rat hippocampal neurons in which the level of AP180 or CALM had been reduced by RNA interference (RNAi).

Nucleolin inhibits G4 oligonucleotide unwinding by Werner helicase.

Background: The Werner protein (WRNp), a member of the RecQ helicase family, is strongly associated with the nucleolus, as is nucleolin (NCL), an important nucleolar constituent protein. Both WRNp and NCL respond to the effects of DNA damaging agents. Therefore, we have investigated if these nuclear proteins interact and if this interaction has a possible functional significance in DNA damage repair.

Translational control of TOP2A influences doxorubicin efficacy.

The cellular abundance of topoisomerase IIα (TOP2A) critically maintains DNA topology after replication and determines the efficacy of TOP2 inhibitors in chemotherapy. Here, we report that the RNA-binding protein HuR, commonly overexpressed in cancers, binds to the TOP2A 3'-untranslated region (3'UTR) and increases TOP2A translation. Reducing HuR levels triggered the recruitment of TOP2A transcripts to RNA-induced silencing complex (RISC) components and to cytoplasmic processing bodies.

Loss of Klotho during melanoma progression leads to increased filamin cleavage, increased Wnt5A expression, and enhanced melanoma cell motility.

We have previously shown that Wnt5A-mediated signaling can promote melanoma metastasis. It has been shown that Wnt signaling is antagonized by the protein Klotho, which has been implicated in aging. We show here that in melanoma cells, expressions of Wnt5A and Klotho are inversely correlated.

Zscan4 regulates telomere elongation and genomic stability in ES cells.

Exceptional genomic stability is one of the hallmarks of mouse embryonic stem (ES) cells. However, the genes contributing to this stability remain obscure. We previously identified Zscan4 as a specific marker for two-cell embryo and ES cells.

Functional significance for a heterogenous ribonucleoprotein A18 signature RNA motif in the 3'-untranslated region of ataxia telangiectasia mutated and Rad3-related (ATR) transcript.

The predominantly nuclear heterogenous ribonucleoprotein A18 (hnRNP A18) translocates to the cytosol in response to cellular stress and increases translation by specifically binding to the 3'-untranslated region (UTR) of several mRNA transcripts and the eukaryotic initiation factor 4G. Here, we identified a 51-nucleotide motif that is present 11.49 times more often in the 3'-UTR of hnRNP A18 mRNA targets than in the UniGene data base.

The Nucleolus Takes Control of Protein Trafficking Under Cellular Stress.

The nucleolus is a highly dynamic nuclear substructure that was originally described as the site of ribosome biogenesis. The advent of proteomic analysis has now allowed the identification of over 4500 nucleolus associated proteins with only about 30% of them associated with ribogenesis (1). The great number of nucleolar proteins not associated with traditionally accepted nucleolar functions indicates a role for the nucleolus in other cellular functions such as mitosis, cell-cycle progression, cell proliferation and many forms of stress response including DNA repair (2).